You don't have to justify yourself. Most all of us on here have dysfunctional relationships of some kind. People on here are supposed to support each other to be healthier and not to judge.

Everybody projects their own stuff on each other's posts, it can't be helped. So it's very understandable that someone who may have been the hurt party of an affair may feel very strongly and lash out.

More importantly, it sounds like your BF has a lot of other problematic stuff going on. Do you keep gravitating to people that aren't good for you?