Is he putting on an act?

Theres this guy who I kinda like, hes totally gorgeous,hes at my school and we are both share one of our classes together but I never talked to him, he always acted really dumb...well he was at my mates place when we went over there one time and he...

turned out to be absolutely hilarious and nice to me...but I just found out that he'd been mean to one of my friends not too long ago, she says if hes nice to me than thats ok...but it still really bugs me! I dunno if hes just putting an act on at school or what...! Should I give up on him?

No of course not. Maybe he just doesn't like your friend. Ever thought of that? People aren't mean to everyone just because they're mean to one person.

yeah, he could just not like your freind
also people can act a bit differently than they would if they were at school
I dont think you should give up on him
if you like him, tell him!
ansdd if you two start becomming good freinds,
you can ask him if he likes your other freind (as a freind!) lol