How to get rid of a guy who really likes me?

Ummmm . . .so there is this creeper following me all the time. I've known him for a couple of years and I know he really likes me. I don't like him back but I don't want to hurt his feelings. It's really annoying and he calls me for help with homework late at night when I'm almost asleep. (I'm 13 and he just turned 15, he was held back and I skipped a grade). He always tries to talk to me and always annoys me. How do I get rid of him without hurting his feelings? (I'm kind of a creeper magnet but most of them wear off after a couple of days, this one doesn't.)