ESH. While in this specific case to side with your stepdaughter is the right move and you are NTA, sounds like your son is just a nobody to you. You sound extremely distant to him.

It must be hella difficult to be raised like this for him. He is a problem in school? Well let's just let him drop out and we homeschool him. Make his life even more difficult. You raised him to be like this and then demonizing him and "save others" from his behavior. While I understand if it's to big of a problem you need a solution but did you go to therapy with him? Or tried to reason with him where this behavior comes from?

Maybe because you are gay your marriage was not the easiest for all of you and you have a lot to go through for your self, understandably, but I think early therapy for your son would have helped him a lot to understand what's going on around him.

With 26 it's hard I guess. You raised an AH but the apple does not fall far from the tree I guess.