One more thing... a couple of you said that the fact that it was Mike's mother who asked him to see it with her made a difference. To me, this indicates a way of thinking, that parents (and indeed other family members) should take priority over other people, and get preferential treatment. For example, if I had incited Mike to a BBQ lunch at my place on Sunday, and then on Saturday his mother invited him around to her place for lunch, would Mike be justified in cancelling my BBQ to attend his mother's lunch? (I'm not trying to be snarky or anything here, I really am confused!)
Going someplace with his mother or going to his mother's is not a "get out of Etiquette Hell free card" if he were to cancel other, pre-existing plans to do so.
He would have had no ulterior motives for going out with his mother (unless she is RICH and offered to buy him a new car on the way home - which I think you might have mentioned). So he was being nice to someone who has done a lot of things for him in the past and doing something with them that they would both enjoy.
I take DS to Harry Potter movies - he may not always want to sit WITH me - but he likes going to the movie with me even though I don't buy huge tubs of popcorn, pizza slices, and all-you-can-drink sodas for him. We laugh at the same things, we have both read the books, and I made him a robe to wear to the next one.............
DD has gone to movies with me, as well, even paying for a couple of them after she turned 20!! But she also goes to movies with her BF (now fiance).
DH has gotten in trouble a couple of times because he said that we would go to a movie when he got back from a trip......only to have that movie be the one on the plane trip home.......and he hates seeing a movie twice. He did take me to see Men In Black after taking the kiddo to see it - because he thought that I would get a big kick out of it, and I was sick the night they went together.
Musing on "what the heck does she mean"? What I mean is that if he had chosen to go see the movie with "Joe" instead of "Mom" - he still did nothing wrong because the two of you had not scheduled a time to go see it. He went to see it with "an old, dear friend" who has a relationship
with him that will probably continue until one of them dies. And he seems to have a good relationship
with that person.
Take it as an indicator that he is capable of lasting relationships
and enjoy the movie - it sounds like he thought it was good enough to see TWICE!
Which I have barely been able to get the DH to do with Star Wars IV through VI, the first three Harry Potter movies, any of the Lord of the Rings movies, or even Star Trek movies.............although he will watch James Bond, Bruce Willis, and Arnold S. movies more than once - he just prefers to have a few months between viewings.........