Well.. I know when someone like someone else, sometimes they tend to be, well, mean. I've even noticed myself doing that occasionally when I meet someone that makes me feel defensive.
That being said, if he was a real nice guy he would recognize that he was letting his feelings hurt you and he would stop and try to walk in love, whether you made him feel defensive or not.
It sounds like though this is a personality issue where he is just being mean and whether he likes you or not is unimportant because who would want to be with someone who hurt them???
So finally, if it were me, I would do my best to walk in love toward him. Be patient kind and so on. I would try to avoid him and respond less. Basically if you don't give them attention they will either feel bored or rejected and hopefully move on.
If you're stuck in a situation with him and he just won't relent and is tormenting you, then stand up to him and tell him to stop. Be strong, be aggressive and value yourself. And remember that your Father in heaven in values you.