I need a little help with a guy.?

So, a guy use to ask me out everyday, and finally i said yes, and then we broke up and have dated a few time since then. He has also dated my best friend, who is much more popular than me. The trouble is, i think about him alot. more than i should. i make it quite clear that i like him,,but it doesnt matter. the really confusing part is, that when his friends arent around, he holds my hand, and flirts with me. He'll hug me, and he will put his face so close to mine, he has to take off his hat. But he wont even touch me when one of his friends is around. It confuses me and it saddens me. I feel like sitting down and crying most of the time. and the problem is, everyone sees how 'perfect' for each other we are. advice? pleaase help.