Aita: I Try To Keep My Friends In Check

First day of school last year, I was starting at a brand new school and didn't know anybody. A guy goes up to me and we become really good friends. Cut to this school year, he and I are in the same class with two of his other friends, but also a bunch of girls that bully him. I learned then that he is actually very misogynistic and homophobic. He goes out of his way to abuse the girls who are bullying him, and he views it as getting revenge. But to me, it seems really rude. In addition to the targeted harassment of any girl, he also blows up and becomes very angry and violent over small issues, like if someone bumps into him. His other two friends aren't getting involved, and I'm the only one who seems concerned. I want to get out of this friendship, but I'm worried my friend will start to actually start executing his plans if I'm not there to stop him. Am I being too controlling? Should I let 'boys be boys'? Or is my friend actually someone that I need to be worried about?