Most Helpful Girl
If he has that genuine attraction to you (which I'm sure he does,) you probably make him nervous.
Of course he doesn't want to visibly show that he is (who does?) and wants to make a good impression, but is still probably figuring out the means to do so. Throw him a friendly smile every now and then, maybe say hi or something so he knows your pretty cool. That may help calm his nerves a bit ^^