Gah. Guy problems.

I'll make this short.
I like this guy.
He is 18.
He is very mature, has a car, job, he is very sweet.
He is also very attractive.
Which is rare these days for me.
Most guys dont appeal to my eye much.
But he stands out.
&& hes one of the few guys I can honestly say I
could see myself with him.
But..
Theres a problem, like always.
He has a girlfriend..
*sigh*
This makes me sad..
&& Im confused.
He was so hitting on my last night.
But maybe thats because I started it?
*shrug*
I guess I'll back off and wait..
Any advice in the mean time.
Should I keep trying or seperate myself from this guy.
(Might I remind you this is rare that I find a guy that I like..) ♥Kaley