When there's nobody else to take the dog out in the freezing cold rain because the entire household is you and your husband and he is at work.
When you realize that dogs don't housetrain themselves, that was your mom doing that and oh guess what now it's your turn.
When you get into a bind and you *don't* tell your parents because it's your thing to deal with.
Mom and Dad don't pay for your Christmas presents to themselves any more

You have to discuss whose family to visit for which holiday, and how that's going to affect vacation time and paychecks.
You're making plans for your wedding anniversary (eeek, less than a month until our 2nd, when did I grow up???)
You go down this list checking off all the ones you do...
