If you want to have a chance with him, you'd have to first know if he's gay or not. In your chats, you'll have to get up the courage to ask him/listen for clues about his personal life. Nothing too invasive, but enough to find the answers you need. The easiest and most common is just to ask if he has a girlfriend (at an appropriate time! Not randomly!!)
If you actually know he's not into guys, you'll have an easier time getting over the crush.
My 5 cents… rather than asking if he has a girlfriend (if he is unsure where you are coming from, or not out to all, he might say yes) I prefer asking (did it recently with a neighbor I had a bit of a crush on) if they have a partner, or, if possible, ask if they have a girlfriend or boyfriend (kind of with an open mind, without necessarily implying anything specific). My neighbor was indeed gay... so my next step was to invite him to kind of a social situation, again, not pressing... in my case, he was not too interested 
sniff.
Best of lucks!!!
D