What's going on in his head?

It's about this guy I kinda like. His behaviour confuses me. I added him on facebook, n he posted a friendly msg on my wall (this happnd just once). But whn I'm around him in real life he tries not 2 look at me. He will smile at me a few times and very very seldom talk to me. I think that I'm making him feel uneasy.. even though I nvr showed that I m attracted to him, I just thought that mayb he sensed smth. I'm trying to show him that I'm nt being clingy, but I'm afraid that I might send d wrong signal that I dnt like him. But what is he thinking? Please help me so I know how to react to this... Our age diff is quite big tho..cud he b thinking I'm too young for him? Thnx, guys.