here's the thing with guys,
guys like challenges. he has to work hard to get to u. u shouldnt give him everything easily, then he'll never be attached to u. usually a guy gets attached to a girl when he works so hard to get to her and still at the end he doesnt get everything...
if u try to do this and this guy isnt willing to work hard for u, then he's not worth it. don't have sex with him as a desperate move to make him fall for u cz he wont, he'll just use u and throw u away.
so what u should do is: tease him! tease him for months! if he sticks around, then he'll become attached to u. if he doesnt, say bye bye and move on! he's not worth ur time