How to talk to him, when he doesnt talk to you anymore?

Ok, well i met this guy and he started talking to me at a football game, were both in the band so we were sitting in the bleachers near eachother, i knew his name and everything but i rlly didnt think he knew me because i nvr rlly talked to him before and im a twin and most ppl dont know which one a am, well the surpriseing thing to me is that he started talking to me and knew my name, so we talked and when we got back from the game (away game) to put our uniforms away we decided to talk to me agian, it was cute because he was sorta following me haha, and then in band in school he'll make little conversation and then he started saying "You need to smile" but know he doesnty seem to talk to me anymore, cause i think, he thinks i dont wanna tal to to him, can someone please give me tips on how to start a conversation with him? well were both shy so its hard to strat a good conversation with him, please and thank you.