They don’t even know they’re being abusive most of the time. Especially women. There’s a picture in society that only men, especially straight men can be abusers and that if anyone else does it it “doesn’t count.”
That’s why a lot of abusive LGBT people can understand if a husband is abusing his wife but don’t understand that when they do the same behaviour it’s abuse too.
We need to teach people that abusers can be anybody.