Does he like me or no? What about his girlfriend?

When a guy says he's commited to his girlfriend, but he stares at you in cl, when you walk by him he looks down or looks to the side. He use to avoid you, he seems nervous around you, when you are having a convo with a friend like you are hungry and he said you should eat cookie, and you said no, and the guy whose commited offers you a piece of brownie and just you, stuff like that, does he like you? btw he's shy and in high school.