It really depends on the guy. He could be a shy guy and thus his interest in you is masked by his avoidance, and yes, that would require you to make a move. Otherwise, he is an egomaniac playing a game and you don't want anything to do with him anyway.

My suggestion would be to feel out a third party who knows both of you and see if you can get a better read on him that way; then react accordingly.

Why don't you try talking to him. See how he reacts. this happened to me once. I was convinced a guy hated me. He was one of my friends in college and when we would go to class together he would sit as far away from me as possible. And later he confessed his undying love to me. It was a little awkward since I had a BF at the time (a BF I later married). But I agree with Michael: it does depend on the guy. He might not even be aware that he is doing this. Do you ignore him too?

No, it means that he has a crush on someone you hangout with frequently. Trying hanging out with other people, other than the ones you normally hangout with and see if he still pops up.