This guy in my class keeps looking at me and saying hi/bye and smiling whenever he sees me but won't say anything else. I can tell that he glances at me a lot during class but he never comes over to me or tries to talk to me even when I am by myself after class. I tried sitting next to him but he still didn't say anything and ended up giving some long explanation about why he's changing seats which I thought was weird but then he ended up looking over at me for the rest of class. It always seems like he wants to say more to me but never does. Why do guys do this? Are they interested in being friends or do they like me?