Have you ever fallen for a guy with a girlfriend?

There is this guy I like for a while now, and I know he likes me back, we are always so cozzy and close to each other but the thing is he has a girlfriend in a far away city. Sometimes he gives me that look, that says it all, other times i feel like he is just being extra nice because we are close. I am lost and confused. Last saturday, we went clubbing together and we ended up dancing all night, but when I got drunk I had to stay away otherwise I would end up kissing him, is this normal? Why doesn’t he understand how much I like him? Is he so blind? I do not know what to do… and one more thing, I have never been jealous from anyone, but I am jealous from his girlfriend for having him !
PS: moving on does not help, i have tried !!