When he asked you if it was okay for him to cut dinner short to go visit his sister, you weren’t direct. You should have said, “It’s not okay with me. I want you all to myself tonight!” But instead you gave a passive aggressive answer by telling him to go, but that if it were you, you’d never do something so rude.
If, after you’re clear, he then pouts for a day and a half, you have to stop being co-dependent and trying to fix something you didn’t cause. It’s very hard for some people to not fix things they think they have responsibility for. Also, you don’t give him the opportunity to get over his disappointment when you’re constantly trying to fix things and assuming it’s you who did something wrong, when really, you’re just answering his question honestly.
I hope that helps. Let me know how things go, and please follow me @AskAprilcom on Twitter.

