What should I do about this guy's behavior?

He's a jerk a needs to get a life if he's going to be insulting you. I say you should completely ignore him, delete him as a friend on Facebook. He's just mad because you're better then him. So he'll waist his time trying to make you feel like crap. This happened to me and I was like, think what you want, but remember you'll always be that jerk. Hope this helps:)