I think I like the guy I set my best friend up with... HELP

But... well, today, I was hanging out with my friend and the guy. We were all talking and (I think it's just because he's really kind and polite) he made lots of eye contact with me. And I learned that he's a black belt like I am. Basically, some bonding happened, and now I feel like maybe I got a little too close... I'm really afraid that that tiny crush I always had on him is going to become something worse, and oh god, I feel awful, but I can't stop thinking about it!