I'm not stooping that low.
He's got my hat and flaunts it in a mocking manner.
Good for you, Bryan. Good for you.
If that makes him feel better about himself, it's to his disadvantage and I won't let it get to me.
That, and it's A HAT.
So I don't like him. Ok... what's the problem, I wonder. I don't hurt him, I don't go out of my way to make him miserable, I don't try to "win" at the games he plays. I just don't interact with him. That's what you do when you do get along with someone.
It's called civilization. Learn it.