How do you know when a guy likes you?

There's this guy I just started liking, I mean everyone thought we liked each other before-but I didn't like him like that than. He's really nice, smart, and cute were like advantage friends, but it's kinda awkward when everyone thinks we like each other. Now that I like him, I just want to know if he likes me back.

His locker is right next to mine-ironic, I know-and we always so good-bye each other at the end of the day. We don't have a lot of classes together so, I can't really tell if he likes me.

I'm not sure if I should confess to him that I like him, or ask my friend to see if he does. I really don't want any of my friends to say anything, because the last time I ask my friend to find out, the guy ended up but creeped out by me and turned into a complete jerk. Plus, If he doesn't like me, I don't what the fact that I like him to ruin our friendship.

So, what should I do?