Try to do somthing fun with all three of ur best friends maybe they will get to know each other better and get along better and dont worry bout him i bet in 3 years u wont even know who he is and boys r idiots no offense to the boys who r reading this
things happen get with your g.f and see if you three can do something one night
menage a trois
Unless you're fat (fat people cant even respect their bodies, so they wont respect others, its a fact. Source: I'm a fat **** too), he should go with the one that loves him as the one he loves will most likely leave him anyways. Given you're age, its normal for your friend to be an idiot, but hopefully, one day, he learns that the fastest road to ******** is being loved.
Yea teenage hormones... just have fun with it until you learn that most guys are just either immature or obsessed with their "success" to the point that it makes them self-obsessed... but UNTIL THEN, realize how much fun being a teenager is. And use protection.