It’s not all that complicated. 🙂
This guy likes you and wants to date you. But he has a girlfriend “at home” who he is on again off again with. Students who are new to college naturally straddle two worlds — their dorm life home and their home town home. So it’s kind of natural to have a double life as a college student.
That said, I think it’s fair to bring up what you’d heard — that he has a girlfriend at home — next time the two of you have coffee or dinner together. Ask him what the deal is. He may not know you know, or else he may not be thinking about it yet, since things haven’t quite progressed to the first date with a kiss at the door stage with you — or, it may not even be true.
But, by no means should you give up on him. It sounds like the beginning of romance, and getting to know him and know if he’s compatible and available is what dating is all about. By getting to know him — and what the deal is with this girlfriend — you’re finding out if he is someone you want to give your heart to, so remember that dating is what you do in order to have fun, but also to find out about the other person, and yourself.
I hope that helps!