It's always things he knows I want him to go to, but he dgaf about
Of course it is - this whole behaviour is a power play, and he gets a huge kick out of every stage:
You begging /persuading him to come, saying how much you want him there
You on tenterhooks as the event draws nearer
Your disappointment when he bails, followed by more begging him to reconsider
If he does deign to accompy you, the fact that you will spend all evening making sure he is happy, walking on eggshells in case he kicks off, not really able to enjoy yourself.
The whole thing is a massive, delicious feast of attention and manipulation for him. Don't ask him to come - get ready cheerfully and call "don't wait up!" as you leave.
Long term : rethink how much you really want to be with this guy.