How do you tell a guy nicely, to back off?

I am 19, in college, and chill being single. I wanted a guy, but the thing is, I am content to enjoy my life without the drama. Well fate decided to entervine and sent me a guy- be careful what you ask for- that I could never see myself with. I am not attracted to him. But he seems to be into me- he makes comments about me being funny, liking my dress style, and keep touching me. I hate that. Touching is personal, and he keeps grabbing my hand, touching my knee, mussing my hair (annoying!) and I can't stand it anymore. I don't want to hurt his feelings, I know where he is coming from, but he keeps inviting himself places, trying to sit next to me. I don't know what to do to make him understand, I cannot ever, ever be with him.How do you tell a guy nicely, to back off?
Trust me, you'll hurt his feelings more if you don't just come right out and tell him you're not interested in him than if you let this continue.



Just curious, if you don't mind me asking, why don't you like him? If you tell me, it will further my research. Please, be honest. If it's because he doesn't have the looks, then say so. If it's because he came on too strong, or whatever. The more I find out about these things the more I'll be able to help give advice.