Post-separation invitation etiquette

[Poppea]

Bill and Betty are still MARRIED.  Therefore it is impossible for him to be part of a social unit with anyone else.  Invite Betty.  Ask her if its okay to invite Bill by himself.  Do not invite the girlfriend of a married man to the same party as his wife.

I would agree with this if they were not separated and actively in the process of an amicable divorce, especially because Carol had nothing to do with the separation or divorce.  I would feel completely differently if Carol contributed to the breakup or if either Bill or Betty had hard feelings about the divorce.  From the information we have, it seems Bill and Betty are not bitter so I see no reason to make things awkward for people who like them both.  Personally, I would want to be trusted to handle situations as an adult, which to me means accepting that the marriage is over (even though the papers are not final) and being cordial and friendly to my ex-spouse and his new SO. Presumably, Betty's kids are around Carol so I see no reason why she would not want to be friendly with her.

I disagree.  No one really knows how Betty would feel if he say her husband with his girlfriend.  She might be okay with it or it might hurt her feelings greatly.  She might be okay with it one day but not the next.  Divorce, even an amicable one is a highly emotionally fraught time.

Maybe I'm a traditionalist, but marriage actually means something to me.  This is a family event.  I wouldn't want Betty's kids to have to deal with dad's girlfriend before the divorce was final nor would I want to have to explain to my kids that the lady holding hands with Mr. Smith is his new girlfriend even though the Smith's aren't divorced yet.  Either you are married or you aren't.  If you are still married you are absolutely not part of any other social unit.

I'm sure the marriage also meant something to Betty and Bill. I would invite Carol with Bill if Betty said it was okay. There doesn't seem to be any point in pretending that Betty and Bill are still in a relationship.

But that wasn't one of the four choices. None of the choice reflect that Betty and the hostess are lifelong good friends and Bill is a longtime spouse of the friend.  The primary relationship is with Betty, not Bill.  I can think of no circumstance where I would go out of my way to befriend the new girlfriend of my BFF's exhusband.

In fact, how on earth would the hosts even know how committed Bill is to Carol if they've never seen them together?  They have barely seen Bill since the divorce and Bill and Al seem to have no independent relationship.

I would not suggest pretending they are still in a happy relationship (ie sending and invitation to Betty addressed to "Bill and Betty". But inviting the girlfriend could be very very hurtful, even if the divorce is amicable, it is often very painful to both parties when a marriage ends, even if it is for the best.

[TurtleDove]

There doesn't seem to be any point in pretending that Betty and Bill are still in a relationship.

Exactly.  I get the sense neither Betty nor Bill are bitter about the divorce, which is a very admirable thing.  This does not translate into "the marriage didn't matter to them" or anything of the sort.  It is an emotionally sound way of dealing with the reality that the marriage had run it's course for whatever reason.

[AllTheThings]

Bill and Betty are still MARRIED.  Therefore it is impossible for him to be part of a social unit with anyone else.  Invite Betty.  Ask her if its okay to invite Bill by himself.  Do not invite the girlfriend of a married man to the same party as his wife.

I would agree with this if they were not separated and actively in the process of an amicable divorce, especially because Carol had nothing to do with the separation or divorce.  I would feel completely differently if Carol contributed to the breakup or if either Bill or Betty had hard feelings about the divorce.  From the information we have, it seems Bill and Betty are not bitter so I see no reason to make things awkward for people who like them both.  Personally, I would want to be trusted to handle situations as an adult, which to me means accepting that the marriage is over (even though the papers are not final) and being cordial and friendly to my ex-spouse and his new SO. Presumably, Betty's kids are around Carol so I see no reason why she would not want to be friendly with her.

I disagree.  No one really knows how Betty would feel if he say her husband with his girlfriend.  She might be okay with it or it might hurt her feelings greatly.  She might be okay with it one day but not the next.  Divorce, even an amicable one is a highly emotionally fraught time.

Maybe I'm a traditionalist, but marriage actually means something to me.  This is a family event.  I wouldn't want Betty's kids to have to deal with dad's girlfriend before the divorce was final nor would I want to have to explain to my kids that the lady holding hands with Mr. Smith is his new girlfriend even though the Smith's aren't divorced yet.  Either you are married or you aren't.  If you are still married you are absolutely not part of any other social unit.

I'm sure the marriage also meant something to Betty and Bill. I would invite Carol with Bill if Betty said it was okay. There doesn't seem to be any point in pretending that Betty and Bill are still in a relationship.

But that wasn't one of the four choices. None of the choice reflect that Betty and the hostess are lifelong good friends and Bill is a longtime spouse of the friend.  The primary relationship is with Betty, not Bill.  I can think of no circumstance where I would go out of my way to befriend the new girlfriend of my BFF's exhusband.

In fact, how on earth would the hosts even know how committed Bill is to Carol if they've never seen them together?  They have barely seen Bill since the divorce and Bill and Al seem to have no independent relationship.

Since this is even an issue, I'm assuming that Ann and Al at least like Bill well enough and want him to be involved, even if the main friendship is between Ann and Betty. Otherwise, they would just not bother with Bill. It's entirely possible to keep up enough with someone's life and relationships without actually seeing them

I would not suggest pretending they are still in a happy relationship (ie sending and invitation to Betty addressed to "Bill and Betty". But inviting the girlfriend could be very very hurtful, even if the divorce is amicable, it is often very painful to both parties when a marriage ends, even if it is for the best.

I would leave it up to Betty to decide if she is uncomfortable. I would not be happy with someone making a decision on my behalf without asking me if it was even an issue in the first place.

[AllTheThings]

Bill and Betty are still MARRIED.  Therefore it is impossible for him to be part of a social unit with anyone else.  Invite Betty.  Ask her if its okay to invite Bill by himself.  Do not invite the girlfriend of a married man to the same party as his wife.

I don't think the two of them can really be called a social unit anymore. Yes they are a legal unit, since legally they are still married. But we are talking social units, and they have broken up. I think Bill is free to be in a social unit with someone else, since he is no longer in one with Betty.

[Poppea]

Bill and Betty are still MARRIED.  Therefore it is impossible for him to be part of a social unit with anyone else.  Invite Betty.  Ask her if its okay to invite Bill by himself.  Do not invite the girlfriend of a married man to the same party as his wife.

I would agree with this if they were not separated and actively in the process of an amicable divorce, especially because Carol had nothing to do with the separation or divorce.  I would feel completely differently if Carol contributed to the breakup or if either Bill or Betty had hard feelings about the divorce.  From the information we have, it seems Bill and Betty are not bitter so I see no reason to make things awkward for people who like them both.  Personally, I would want to be trusted to handle situations as an adult, which to me means accepting that the marriage is over (even though the papers are not final) and being cordial and friendly to my ex-spouse and his new SO. Presumably, Betty's kids are around Carol so I see no reason why she would not want to be friendly with her.

I disagree.  No one really knows how Betty would feel if he say her husband with his girlfriend.  She might be okay with it or it might hurt her feelings greatly.  She might be okay with it one day but not the next.  Divorce, even an amicable one is a highly emotionally fraught time.

Maybe I'm a traditionalist, but marriage actually means something to me.  This is a family event.  I wouldn't want Betty's kids to have to deal with dad's girlfriend before the divorce was final nor would I want to have to explain to my kids that the lady holding hands with Mr. Smith is his new girlfriend even though the Smith's aren't divorced yet.  Either you are married or you aren't.  If you are still married you are absolutely not part of any other social unit.

I'm sure the marriage also meant something to Betty and Bill. I would invite Carol with Bill if Betty said it was okay. There doesn't seem to be any point in pretending that Betty and Bill are still in a relationship.

But that wasn't one of the four choices. None of the choice reflect that Betty and the hostess are lifelong good friends and Bill is a longtime spouse of the friend.  The primary relationship is with Betty, not Bill.  I can think of no circumstance where I would go out of my way to befriend the new girlfriend of my BFF's exhusband.

In fact, how on earth would the hosts even know how committed Bill is to Carol if they've never seen them together?  They have barely seen Bill since the divorce and Bill and Al seem to have no independent relationship.

Since this is even an issue, I'm assuming that Ann and Al at least like Bill well enough and want him to be involved, even if the main friendship is between Ann and Betty. Otherwise, they would just not bother with Bill. It's entirely possible to keep up enough with someone's life and relationships without actually seeing them

I would not suggest pretending they are still in a happy relationship (ie sending and invitation to Betty addressed to "Bill and Betty". But inviting the girlfriend could be very very hurtful, even if the divorce is amicable, it is often very painful to both parties when a marriage ends, even if it is for the best.

I would leave it up to Betty to decide if she is uncomfortable. I would not be happy with someone making a decision on my behalf without asking me if it was even an issue in the first place.

I suggested that Betty be asked , however the OP listed four choices, and asking Betty for her input was not one of the listed choices.  If Betty cannot be consulted it is better to not invite Carol.

[AllTheThings]

Bill and Betty are still MARRIED.  Therefore it is impossible for him to be part of a social unit with anyone else.  Invite Betty.  Ask her if its okay to invite Bill by himself.  Do not invite the girlfriend of a married man to the same party as his wife.

I would agree with this if they were not separated and actively in the process of an amicable divorce, especially because Carol had nothing to do with the separation or divorce.  I would feel completely differently if Carol contributed to the breakup or if either Bill or Betty had hard feelings about the divorce.  From the information we have, it seems Bill and Betty are not bitter so I see no reason to make things awkward for people who like them both.  Personally, I would want to be trusted to handle situations as an adult, which to me means accepting that the marriage is over (even though the papers are not final) and being cordial and friendly to my ex-spouse and his new SO. Presumably, Betty's kids are around Carol so I see no reason why she would not want to be friendly with her.

I disagree.  No one really knows how Betty would feel if he say her husband with his girlfriend.  She might be okay with it or it might hurt her feelings greatly.  She might be okay with it one day but not the next.  Divorce, even an amicable one is a highly emotionally fraught time.

Maybe I'm a traditionalist, but marriage actually means something to me.  This is a family event.  I wouldn't want Betty's kids to have to deal with dad's girlfriend before the divorce was final nor would I want to have to explain to my kids that the lady holding hands with Mr. Smith is his new girlfriend even though the Smith's aren't divorced yet.  Either you are married or you aren't.  If you are still married you are absolutely not part of any other social unit.

I'm sure the marriage also meant something to Betty and Bill. I would invite Carol with Bill if Betty said it was okay. There doesn't seem to be any point in pretending that Betty and Bill are still in a relationship.

But that wasn't one of the four choices. None of the choice reflect that Betty and the hostess are lifelong good friends and Bill is a longtime spouse of the friend.  The primary relationship is with Betty, not Bill.  I can think of no circumstance where I would go out of my way to befriend the new girlfriend of my BFF's exhusband.

In fact, how on earth would the hosts even know how committed Bill is to Carol if they've never seen them together?  They have barely seen Bill since the divorce and Bill and Al seem to have no independent relationship.

Since this is even an issue, I'm assuming that Ann and Al at least like Bill well enough and want him to be involved, even if the main friendship is between Ann and Betty. Otherwise, they would just not bother with Bill. It's entirely possible to keep up enough with someone's life and relationships without actually seeing them

I would not suggest pretending they are still in a happy relationship (ie sending and invitation to Betty addressed to "Bill and Betty". But inviting the girlfriend could be very very hurtful, even if the divorce is amicable, it is often very painful to both parties when a marriage ends, even if it is for the best.

I would leave it up to Betty to decide if she is uncomfortable. I would not be happy with someone making a decision on my behalf without asking me if it was even an issue in the first place.

I suggested that Betty be asked , however the OP listed four choices, and asking Betty for her input was not one of the listed choices.  If Betty cannot be consulted it is better to not invite Carol.

I assumed that the choices listed were just things that the OP had already thought of, and just didn't consider asking Betty what she wanted. I don't think we have to stick to the mentioned choices in order to give advice, and I don't see why Betty couldn't be consulted about this.

[Poppea]

Bill and Betty are still MARRIED.  Therefore it is impossible for him to be part of a social unit with anyone else.  Invite Betty.  Ask her if its okay to invite Bill by himself.  Do not invite the girlfriend of a married man to the same party as his wife.

I don't think the two of them can really be called a social unit anymore. Yes they are a legal unit, since legally they are still married. But we are talking social units, and they have broken up. I think Bill is free to be in a social unit with someone else, since he is no longer in one with Betty.

The question isn't whether Bill and Betty are still a social unit, it is whether Bill, still married can form a social unit with a new partner while still married.  He cannot legally or socially.  Until he is divorced he can date, have a girlfriend, even live with her, but polite society does not recognize them as  "social unit" until Bill is divorced.

[AllTheThings]

Bill and Betty are still MARRIED.  Therefore it is impossible for him to be part of a social unit with anyone else.  Invite Betty.  Ask her if its okay to invite Bill by himself.  Do not invite the girlfriend of a married man to the same party as his wife.

I don't think the two of them can really be called a social unit anymore. Yes they are a legal unit, since legally they are still married. But we are talking social units, and they have broken up. I think Bill is free to be in a social unit with someone else, since he is no longer in one with Betty.

The question isn't whether Bill and Betty are still a social unit, it is whether Bill, still married can form a social unit with a new partner while still married.  He cannot legally or socially.  Until he is divorced he can date, have a girlfriend, even live with her, but polite society does not recognize them as  "social unit" until Bill is divorced.

Why can't he be in a new unit socially? The social part of his marriage is over, with only the legal part left. Just because "polite society" doesn't approve of something doesn't mean everyone has to go along with that.

[TurtleDove]

polite society does not recognize them as  "social unit" until Bill is divorced.

Real people do, however, especially in situations like this where they are separated and the divorce is in the works.  I don't think it is polite to actively show judgment toward Bill, Betty and Carol by pretending Bill and Betty are still happily married, or to actively show judgment about divorce by pretending that Bill has not found companionship/love again.  To me, since the divorce is amicable especially, I would want Bill and Betty to both be happy, and it seems they are....and Carol is a part of that.

[Poppea]

Bill and Betty are still MARRIED.  Therefore it is impossible for him to be part of a social unit with anyone else.  Invite Betty.  Ask her if its okay to invite Bill by himself.  Do not invite the girlfriend of a married man to the same party as his wife.

I would agree with this if they were not separated and actively in the process of an amicable divorce, especially because Carol had nothing to do with the separation or divorce.  I would feel completely differently if Carol contributed to the breakup or if either Bill or Betty had hard feelings about the divorce.  From the information we have, it seems Bill and Betty are not bitter so I see no reason to make things awkward for people who like them both.  Personally, I would want to be trusted to handle situations as an adult, which to me means accepting that the marriage is over (even though the papers are not final) and being cordial and friendly to my ex-spouse and his new SO. Presumably, Betty's kids are around Carol so I see no reason why she would not want to be friendly with her.

I disagree.  No one really knows how Betty would feel if he say her husband with his girlfriend.  She might be okay with it or it might hurt her feelings greatly.  She might be okay with it one day but not the next.  Divorce, even an amicable one is a highly emotionally fraught time.

Maybe I'm a traditionalist, but marriage actually means something to me.  This is a family event.  I wouldn't want Betty's kids to have to deal with dad's girlfriend before the divorce was final nor would I want to have to explain to my kids that the lady holding hands with Mr. Smith is his new girlfriend even though the Smith's aren't divorced yet.  Either you are married or you aren't.  If you are still married you are absolutely not part of any other social unit.

I'm sure the marriage also meant something to Betty and Bill. I would invite Carol with Bill if Betty said it was okay. There doesn't seem to be any point in pretending that Betty and Bill are still in a relationship.

But that wasn't one of the four choices. None of the choice reflect that Betty and the hostess are lifelong good friends and Bill is a longtime spouse of the friend.  The primary relationship is with Betty, not Bill.  I can think of no circumstance where I would go out of my way to befriend the new girlfriend of my BFF's exhusband.

In fact, how on earth would the hosts even know how committed Bill is to Carol if they've never seen them together?  They have barely seen Bill since the divorce and Bill and Al seem to have no independent relationship.

Since this is even an issue, I'm assuming that Ann and Al at least like Bill well enough and want him to be involved, even if the main friendship is between Ann and Betty. Otherwise, they would just not bother with Bill. It's entirely possible to keep up enough with someone's life and relationships without actually seeing them

I would not suggest pretending they are still in a happy relationship (ie sending and invitation to Betty addressed to "Bill and Betty". But inviting the girlfriend could be very very hurtful, even if the divorce is amicable, it is often very painful to both parties when a marriage ends, even if it is for the best.

I would leave it up to Betty to decide if she is uncomfortable. I would not be happy with someone making a decision on my behalf without asking me if it was even an issue in the first place.

I suggested that Betty be asked , however the OP listed four choices, and asking Betty for her input was not one of the listed choices.  If Betty cannot be consulted it is better to not invite Carol.

I assumed that the choices listed were just things that the OP had already thought of, and just didn't consider asking Betty what she wanted. I don't think we have to stick to the mentioned choices in order to give advice, and I don't see why Betty couldn't be consulted about this.

Asking Betty is the obvious choice.  Which is why I think that the OP might be a friend of Carol.  It makes no sense not to simply call up your BFF and just ask her what she would like. 

In real life I had a friend call me in tears during her very amicable divorce (which she iniated) because a mutual friend had introduced her STBX to a woman her dated very casually.  It was fairly illogical, but she was still very very hurt.  Some of the hurt was feeling that he had moved on so quickly and a fear that her social circle might be regrouping without her but with him.

[AllTheThings]

Bill and Betty are still MARRIED.  Therefore it is impossible for him to be part of a social unit with anyone else.  Invite Betty.  Ask her if its okay to invite Bill by himself.  Do not invite the girlfriend of a married man to the same party as his wife.

I would agree with this if they were not separated and actively in the process of an amicable divorce, especially because Carol had nothing to do with the separation or divorce.  I would feel completely differently if Carol contributed to the breakup or if either Bill or Betty had hard feelings about the divorce.  From the information we have, it seems Bill and Betty are not bitter so I see no reason to make things awkward for people who like them both.  Personally, I would want to be trusted to handle situations as an adult, which to me means accepting that the marriage is over (even though the papers are not final) and being cordial and friendly to my ex-spouse and his new SO. Presumably, Betty's kids are around Carol so I see no reason why she would not want to be friendly with her.

I disagree.  No one really knows how Betty would feel if he say her husband with his girlfriend.  She might be okay with it or it might hurt her feelings greatly.  She might be okay with it one day but not the next.  Divorce, even an amicable one is a highly emotionally fraught time.

Maybe I'm a traditionalist, but marriage actually means something to me.  This is a family event.  I wouldn't want Betty's kids to have to deal with dad's girlfriend before the divorce was final nor would I want to have to explain to my kids that the lady holding hands with Mr. Smith is his new girlfriend even though the Smith's aren't divorced yet.  Either you are married or you aren't.  If you are still married you are absolutely not part of any other social unit.

I'm sure the marriage also meant something to Betty and Bill. I would invite Carol with Bill if Betty said it was okay. There doesn't seem to be any point in pretending that Betty and Bill are still in a relationship.

But that wasn't one of the four choices. None of the choice reflect that Betty and the hostess are lifelong good friends and Bill is a longtime spouse of the friend.  The primary relationship is with Betty, not Bill.  I can think of no circumstance where I would go out of my way to befriend the new girlfriend of my BFF's exhusband.

In fact, how on earth would the hosts even know how committed Bill is to Carol if they've never seen them together?  They have barely seen Bill since the divorce and Bill and Al seem to have no independent relationship.

Since this is even an issue, I'm assuming that Ann and Al at least like Bill well enough and want him to be involved, even if the main friendship is between Ann and Betty. Otherwise, they would just not bother with Bill. It's entirely possible to keep up enough with someone's life and relationships without actually seeing them

I would not suggest pretending they are still in a happy relationship (ie sending and invitation to Betty addressed to "Bill and Betty". But inviting the girlfriend could be very very hurtful, even if the divorce is amicable, it is often very painful to both parties when a marriage ends, even if it is for the best.

I would leave it up to Betty to decide if she is uncomfortable. I would not be happy with someone making a decision on my behalf without asking me if it was even an issue in the first place.

I suggested that Betty be asked , however the OP listed four choices, and asking Betty for her input was not one of the listed choices.  If Betty cannot be consulted it is better to not invite Carol.

I assumed that the choices listed were just things that the OP had already thought of, and just didn't consider asking Betty what she wanted. I don't think we have to stick to the mentioned choices in order to give advice, and I don't see why Betty couldn't be consulted about this.

Asking Betty is the obvious choice.  Which is why I think that the OP might be a friend of Carol.  It makes no sense not to simply call up your BFF and just ask her what she would like. 

In real life I had a friend call me in tears during her very amicable divorce (which she iniated) because a mutual friend had introduced her STBX to a woman her dated very casually.  It was fairly illogical, but she was still very very hurt.  Some of the hurt was feeling that he had moved on so quickly and a fear that her social circle might be regrouping without her but with him.

I think if OP is Carol or friends with Carol, then Betty's happiness isn't really anything she can control. If that is the case, I would suggest to either go or decline based on whether or not she would be comfortable enough to go.

[Poppea]

polite society does not recognize them as  "social unit" until Bill is divorced.

Real people do, however, especially in situations like this where they are separated and the divorce is in the works.  I don't think it is polite to actively show judgment toward Bill, Betty and Carol by pretending Bill and Betty are still happily married, or to actively show judgment about divorce by pretending that Bill has not found companionship/love again.  To me, since the divorce is amicable especially, I would want Bill and Betty to both be happy, and it seems they are....and Carol is a part of that.

Real people and polite society are not mutually exclusive among my friends. 

You are setting up a false construct where you are pretending that I said Bill and Betty are a social unit when that is not true at all.  I have specifically stated that Betty's BFF should put her wishes first.  If Betty cannot be consulted, Ann should not invite Carol becasue that would be assuming that Betty was okay with the relationship. "Amicable divorce" and watching your STBX hang out with his girlfriend at your BFF's house are not necessarily the same thing.

[Poppea]

Bill and Betty are still MARRIED.  Therefore it is impossible for him to be part of a social unit with anyone else.  Invite Betty.  Ask her if its okay to invite Bill by himself.  Do not invite the girlfriend of a married man to the same party as his wife.

I would agree with this if they were not separated and actively in the process of an amicable divorce, especially because Carol had nothing to do with the separation or divorce.  I would feel completely differently if Carol contributed to the breakup or if either Bill or Betty had hard feelings about the divorce.  From the information we have, it seems Bill and Betty are not bitter so I see no reason to make things awkward for people who like them both.  Personally, I would want to be trusted to handle situations as an adult, which to me means accepting that the marriage is over (even though the papers are not final) and being cordial and friendly to my ex-spouse and his new SO. Presumably, Betty's kids are around Carol so I see no reason why she would not want to be friendly with her.

I disagree.  No one really knows how Betty would feel if he say her husband with his girlfriend.  She might be okay with it or it might hurt her feelings greatly.  She might be okay with it one day but not the next.  Divorce, even an amicable one is a highly emotionally fraught time.

Maybe I'm a traditionalist, but marriage actually means something to me.  This is a family event.  I wouldn't want Betty's kids to have to deal with dad's girlfriend before the divorce was final nor would I want to have to explain to my kids that the lady holding hands with Mr. Smith is his new girlfriend even though the Smith's aren't divorced yet.  Either you are married or you aren't.  If you are still married you are absolutely not part of any other social unit.

I'm sure the marriage also meant something to Betty and Bill. I would invite Carol with Bill if Betty said it was okay. There doesn't seem to be any point in pretending that Betty and Bill are still in a relationship.

But that wasn't one of the four choices. None of the choice reflect that Betty and the hostess are lifelong good friends and Bill is a longtime spouse of the friend.  The primary relationship is with Betty, not Bill.  I can think of no circumstance where I would go out of my way to befriend the new girlfriend of my BFF's exhusband.

In fact, how on earth would the hosts even know how committed Bill is to Carol if they've never seen them together?  They have barely seen Bill since the divorce and Bill and Al seem to have no independent relationship.

Since this is even an issue, I'm assuming that Ann and Al at least like Bill well enough and want him to be involved, even if the main friendship is between Ann and Betty. Otherwise, they would just not bother with Bill. It's entirely possible to keep up enough with someone's life and relationships without actually seeing them

I would not suggest pretending they are still in a happy relationship (ie sending and invitation to Betty addressed to "Bill and Betty". But inviting the girlfriend could be very very hurtful, even if the divorce is amicable, it is often very painful to both parties when a marriage ends, even if it is for the best.

I would leave it up to Betty to decide if she is uncomfortable. I would not be happy with someone making a decision on my behalf without asking me if it was even an issue in the first place.

I suggested that Betty be asked , however the OP listed four choices, and asking Betty for her input was not one of the listed choices.  If Betty cannot be consulted it is better to not invite Carol.

I assumed that the choices listed were just things that the OP had already thought of, and just didn't consider asking Betty what she wanted. I don't think we have to stick to the mentioned choices in order to give advice, and I don't see why Betty couldn't be consulted about this.

Asking Betty is the obvious choice.  Which is why I think that the OP might be a friend of Carol.  It makes no sense not to simply call up your BFF and just ask her what she would like. 

In real life I had a friend call me in tears during her very amicable divorce (which she iniated) because a mutual friend had introduced her STBX to a woman her dated very casually.  It was fairly illogical, but she was still very very hurt.  Some of the hurt was feeling that he had moved on so quickly and a fear that her social circle might be regrouping without her but with him.

I think if OP is Carol or friends with Carol, then Betty's happiness isn't really anything she can control. If that is the case, I would suggest to either go or decline based on whether or not she would be comfortable enough to go.

If I were Carol the big "if" for me would be if I have interacted with the kids and/or Betty before.  I wouldn't want to meet them for the first time at Betty's BFF's house.  If I had met Betty and had spent time with the kids already then I would be okay with going.

[AllTheThings]

polite society does not recognize them as  "social unit" until Bill is divorced.

Real people do, however, especially in situations like this where they are separated and the divorce is in the works.  I don't think it is polite to actively show judgment toward Bill, Betty and Carol by pretending Bill and Betty are still happily married, or to actively show judgment about divorce by pretending that Bill has not found companionship/love again.  To me, since the divorce is amicable especially, I would want Bill and Betty to both be happy, and it seems they are....and Carol is a part of that.

Real people and polite society are not mutually exclusive among my friends. 

You are setting up a false construct where you are pretending that I said Bill and Betty are a social unit when that is not true at all.  I have specifically stated that Betty's BFF should put her wishes first.  If Betty cannot be consulted, Ann should not invite Carol becasue that would be assuming that Betty was okay with the relationship. "Amicable divorce" and watching your STBX hang out with his girlfriend at your BFF's house are not necessarily the same thing.

I do not think that anyone is saying that you believe that Bill and Betty are not a social unit. I am saying that because Bill is no longer in one, there doesn't seem to be any reason why he can't be part of a new one.

[AllTheThings]

Bill and Betty are still MARRIED.  Therefore it is impossible for him to be part of a social unit with anyone else.  Invite Betty.  Ask her if its okay to invite Bill by himself.  Do not invite the girlfriend of a married man to the same party as his wife.

I would agree with this if they were not separated and actively in the process of an amicable divorce, especially because Carol had nothing to do with the separation or divorce.  I would feel completely differently if Carol contributed to the breakup or if either Bill or Betty had hard feelings about the divorce.  From the information we have, it seems Bill and Betty are not bitter so I see no reason to make things awkward for people who like them both.  Personally, I would want to be trusted to handle situations as an adult, which to me means accepting that the marriage is over (even though the papers are not final) and being cordial and friendly to my ex-spouse and his new SO. Presumably, Betty's kids are around Carol so I see no reason why she would not want to be friendly with her.

I disagree.  No one really knows how Betty would feel if he say her husband with his girlfriend.  She might be okay with it or it might hurt her feelings greatly.  She might be okay with it one day but not the next.  Divorce, even an amicable one is a highly emotionally fraught time.

Maybe I'm a traditionalist, but marriage actually means something to me.  This is a family event.  I wouldn't want Betty's kids to have to deal with dad's girlfriend before the divorce was final nor would I want to have to explain to my kids that the lady holding hands with Mr. Smith is his new girlfriend even though the Smith's aren't divorced yet.  Either you are married or you aren't.  If you are still married you are absolutely not part of any other social unit.

I'm sure the marriage also meant something to Betty and Bill. I would invite Carol with Bill if Betty said it was okay. There doesn't seem to be any point in pretending that Betty and Bill are still in a relationship.

But that wasn't one of the four choices. None of the choice reflect that Betty and the hostess are lifelong good friends and Bill is a longtime spouse of the friend.  The primary relationship is with Betty, not Bill.  I can think of no circumstance where I would go out of my way to befriend the new girlfriend of my BFF's exhusband.

In fact, how on earth would the hosts even know how committed Bill is to Carol if they've never seen them together?  They have barely seen Bill since the divorce and Bill and Al seem to have no independent relationship.

Since this is even an issue, I'm assuming that Ann and Al at least like Bill well enough and want him to be involved, even if the main friendship is between Ann and Betty. Otherwise, they would just not bother with Bill. It's entirely possible to keep up enough with someone's life and relationships without actually seeing them

I would not suggest pretending they are still in a happy relationship (ie sending and invitation to Betty addressed to "Bill and Betty". But inviting the girlfriend could be very very hurtful, even if the divorce is amicable, it is often very painful to both parties when a marriage ends, even if it is for the best.

I would leave it up to Betty to decide if she is uncomfortable. I would not be happy with someone making a decision on my behalf without asking me if it was even an issue in the first place.

I suggested that Betty be asked , however the OP listed four choices, and asking Betty for her input was not one of the listed choices.  If Betty cannot be consulted it is better to not invite Carol.

I assumed that the choices listed were just things that the OP had already thought of, and just didn't consider asking Betty what she wanted. I don't think we have to stick to the mentioned choices in order to give advice, and I don't see why Betty couldn't be consulted about this.

Asking Betty is the obvious choice.  Which is why I think that the OP might be a friend of Carol.  It makes no sense not to simply call up your BFF and just ask her what she would like. 

In real life I had a friend call me in tears during her very amicable divorce (which she iniated) because a mutual friend had introduced her STBX to a woman her dated very casually.  It was fairly illogical, but she was still very very hurt.  Some of the hurt was feeling that he had moved on so quickly and a fear that her social circle might be regrouping without her but with him.

I think if OP is Carol or friends with Carol, then Betty's happiness isn't really anything she can control. If that is the case, I would suggest to either go or decline based on whether or not she would be comfortable enough to go.

If I were Carol the big "if" for me would be if I have interacted with the kids and/or Betty before.  I wouldn't want to meet them for the first time at Betty's BFF's house.  If I had met Betty and had spent time with the kids already then I would be okay with going.

That's what I would do. A big party like that probably isn't the best place for introductions.