Does he like me !?!?!?!?!?!?!?!?!?!?!?

So, i've liked this guy since the beginning of the school year, and we only have two weeks left of school and he hasnt asked me out! I mean, i'm not ugly, i think i'm actually kind of pretty. he's dating my friend right now, this is the third time they've gone out this year :/ anyway, a bunch of my friends that have classes with me & him agree that he likes me. he's kind of a player& flirts with lots of other girls, but i think that just makes me want him more! he definetly flirts with me, though. even when he's dating someone else, but i try not to flirt back, cuz i dont want anyone thinking hes cheating with me, i'm not a slut. but when he's single, i'll sit on his lap, and cute stuff like that. we've kissed before, too, but just a kiss, not making out. so guys, why is he dating someone else, when even other people agree that he likes me!? :/