What does it mean when a guy does this?

In my class there's a guy who's a little shy. He may know I like him through one of his friends. In class, we were all standing up and I was leaning on a tall desk with my hands gripping the sides. He stood quite close to me (the room was crowded) and his hip/waist area near his crotch touched my knuckle slightly. He didn't move for a few minutes. Does this mean anything, did he even feel my hand there? And surely he would have seen it? Thanks :)