I like my ex boyfriends best friend. Idk what to do!?

Me and my ex went out for like a year. He has a new girlfriend now/: I have a class with her and wanna punch her whenever I see her. He has like a posey of good friends and recently I've started to notice that I like one of them like alot. I feel like he was there all along and I should of never went out with my ex cause i think I really like this kid. He's sooooo hot a major juicehead gorilla in snookis words<3 idk what to do about it though...