Backstory: a couple months ago I was talking to a guy and we got really close and I didn't know that he was talking to her too and he promised he would date her but then we started dating (we broke up). This made the girl not like me so we are not friends

Now: That's girl(call her Emma) and her friend suddenly saved ally my best friend's photos into camera roll and then blocked her (on Snapchat). My friend she is really sweet so she wasn't going to ask anything. THEN Emma was chatting the most about her saying "she's a bitch and she chats sh*t about everyone" and my friend is the sweetest girl like when I have something to say about someone she stops me.

So I was like what the hell so me and my friend went up to Emma and was like "you need to apologise" and she was denying it when there were multiple witnesses and then why she finally admitted it I was like "you have never even spoken to her, are you weird, do you need attention that much. Are you that irrelevant?" AND THEN she was laughing like it was a joke and she went right up in my friends face and said "do something then"

And my friend she hates violence so I stepped in and punched her ofc, it's just what friends do, and then she's on the ground and I'm punching her and then some teachers come and we get pulled apart.THE NEXT DAY she has a black eye and he nose is swollen. I want to know AITA for giving this girl a black eye??