Childish boy

There's this guy who I always catch looking at me and who talks about me ( mean things I'm assuming) to his friends whenever he sees me, but he won't say nothing to me. What should I do, just ignore him or respond. And also, why is he doing this?

If there's a guy you don't know, saying things to people you don't know, does it matter? He's kind of a wimp for talking about you behind your back or having nothing better to do with his time, but that's his problem and not yours. If he starts talking to your friends or you notice your reputation is getting degraded because of what he's saying, then I'd say is the time to stand up to him and ask him to stop. But if the rest of your life is unaffected by his childish actions, try not to worry about it.

what does he say baout you

That's the thing, I don't know?

Just ignore him, he is prob being immature and the more you show him he is getting under your skin the more he will keep doing it, just smile and walk away and that will burn him more.