What should i do to get this guy?

So there is a guy that I really like and we talk a lot on facebook but we have never actually talked in person because we don't see each other very often. He knows I like him and he wont tell anyone how he feels about me. He gets shy around girls so consequently hes never had a girlfriend. There is an age difference, I am a few years younger and the fact that hes older intimidates me slightly. I don't know what to do to get him to ask me out.