Does he like me?

If he like you . Than the picking on you says to me that he is flirting with you . Or he's trying to make another girl jealous . Trust me guys do that sometimes . Just try to talk to him more and give him signals that you like him . ( smiles, look at him . Etc)

Yes, at your age, playful joking tends to be the most common way to show affection . After all, it's easier to be flirty than to be serious, since the latter usually results in a yes or no answer . Show that you like him, get to know him outside of class, and decide whether or not you would both be interested in dating each other .