I need Advise. Falling in love with a taken Guy.?

There is this guy "Z"... We have been friends since the begining of school and hes a really sweet guy. He has had a gf for almost 2 years now. So i never even looked at him that way. well they broke up about a month ago and he started talking to me more and more. I fell for him so fast. He can be a "flirt" with alot of girls and im well aware of a few girls that he "like(d)(s)"... We started hanging out every weekend, going to church togeather, youth group, ect. we were togeather most days. He kissed me (my first kiss) and i was so happy, and yet so sad because he wasnt my boyfried. well this went on for like 2 more weeks. Now he's back with his ex Girlfriend......... We still hang out every weekend, and still flirt, and this weekend he kept 'snuggling' with me. I dont understand what he wantss. Ive talked to him about it before he says hes never alowed to see his gf, so my thought is well whats the point then?! he says he doesnt know. We talk all the time, flirt, snggle, talk on the phone for hours and hours. It is the one thing in my life that makes me really happy. and yet every time we hang up, or he leaves, i feel so sad. i feel like im a bad person because he has a gf, i feel like im setting myself up to be hurt but i cant stop my self...... I dont really have a question. but i need some advise. I hate feeling like im being stupid, but getting over him doesnt seem like an option.