Growing up in a home where abused by the father of my younger siblings, OP is NOT THE ASSHOLE. My stepdad was AWFUL to me, even my mother admits it now that they are divorced. Being said, I’ll shit about in front of my siblings but if they get upset I stop. That is their dad and they are a part of him.

OP may have had a different relationship, but that is her dad.

How would you feel if someone told you they absolutely despised who and where you came from? Wouldn’t you also immediately feel estranged from that person? He’s an asshole for not respecting that’s her dad. She’s an asshole for glazing over their shitty relationship. Mom in my opinion is the asshole. She should put her foot down- what happened between your father and brother is not YOUR fault. You shouldn’t apologize for the ill-doings of your parent and she should never make you feel like that’s your responsibility.