how did you know he has a crush on you? maybe.. he doesn't want you to know since he knows you already have a bf. so maybe he's just trying really hard to keep his feelings bottled up not to ruin your relationship w/ your bf.

Unless.. he's like a flirty and stuff... in that case, just tell him that you like him as a friend and you don't feel comfortable when he flirts all the time!

If not, I'll rather not confront him, cuz afterall, it's not against the law to have a crush on somebody! It's not like he won't like you anymore after you tell him you don't like him!