I'm not sure if he's flirting with me or not...?

I actually had a similar problem. One day, this kid Ryan started to wave, wink at me, and make Kiss faces. I actually thought it was weird because he and his friends also kept slapping their s in front of me....Anyways, even though he flirted with me, it was all a joke. He had had a girlfriend already and I knew that. This guy could probably be teasing you. But he could like you. My advice is to look out for any signs he might be teasing with you. If he's like, teasing you a way a little boy teases a little girl when they like them, he probably likes you. But my advice is to pretend you didn't notice anything until he shows a sign of making a move. Then decide whether or not YOU like HIM. Then take it from there. Best of luck!