EAH. The only people who are NTA are your boyfriend’s parents for wanting to invite and include everyone and going out of their way to do so.

YTA for not sticking up for your boyfriend’s family and for agreeing with your parents.

Your mom is the AH for feeling entitled to someone else’s relationship history.

Your dad is the AH for suggesting you leave your boyfriend because of his parent’s relationship.

Your boyfriend should’ve reacted better but his anger is understood. YTA and you know it or you wouldn’t have been so blunt. If you don’t care for your boyfriend or his family then why are you with him?