Sex w a guy who has a gf...

So.. There's been a guy I had the smallest crush on and we've been pretty coridal and we pretty much can talk about anything with one another. Then, we were texting and then all of a sudden cuddling came up (as I mentioned it not even thinking he'd actually want to bc we don't have that kind of relationship) also, I didn't say that I wanted to cuddle with him, but cuddle in general. And so when when he asked I said laughed it off and then realized he was serious. And so then I said sure and then he told me he was going to be honest & that he's with someone, and they've been beefing a lot lately & I was like damn, I'm gonna respect your relationship and not cross the line. And so he was perfectly fine with that & we talked about it a little more and I was like dang, I'd love to cuddle though and he was like nothing OD is going to happen if he do, and so I was freaking out & he told me to relax & I was alright cool. So I get to his dorm and we cuddle, talk, watch tv and then he started getting touchy feely and then fingered me for a while and it got heated and then we started having sex.. I know it's wrong as a female bc he told me before hand that he had a gf and I shouldn't have done it knowing that. And I feel like now I have a bigger crush on him, but now that this all happened all I can think of, is that he's probably not shit now that he had sex with me and still is with his girlfriend. I really just need advice and someone to keep it real with me. We're both in college btw.