Does he like me back?

I think he likes you. The reason he hasn't spoken to you is because he's shy. He probably just doesn't know how to make the first move. I think you should talk to him. If he's making this such a big deal, he obviously has feelings for you, but he doesn't know how to express them towards you because both of you were good friends. So during lunch, go up to his table and tell him that you need to talk to him. I'm sure both of you will work things out!