I like this guy 2 years older than me?

Ok, well there's this guy who's 16, and I really like him. I've started noticing him around the school practically every day, and it's bugging me! He was my 'nco' (mentor) for my bronze duke of Edinburgh expedition. We hit it off and he was so nice to me and we found we had loads in common. (it sounds trivial, but all the mentors got pizza that night and all the juniors had to have rations, and he only gave me and one other my partner some when te rest of his group asked for some too) since then we've not really spoken, we've smiled at eachother and had that 'eyes meet moment' and apparently during our ccf parade he was looking and smiling at me quite a lot... We've had convos on facebook, about an hour long at night and he's asked about my family and by brother (who's at the same uni as his sister) and I really really like him! He's also agreed to be in a choir that someone asked me to organise for a Carol service. I don't know if he likes me though cos in my opinion there are FAR prettier girls in the school than me! How do I talk to him, or get his number, or subtley suggest I could like him? Thankyou so much!!!!!