<human>: Could you distill the essence of the text into 1-3 sentences?

I had been seeing this guy I attend university with on and off since October, and for the past 2 months we had become increasingly close. Yes, we'd slept together a few times, but sometimes he'd come over and we'd just watch movies/cuddle/talk. We went to see plays, we were supposed to go on a date this weekend. He had increasingly mentioned me meeting his friends and family. Said how much he didn't want to leave when he had to go from me and go to work.

However, last night, as we were both hanging out and drinking in my dorm (neither of us were drunk, by the way), we come up on the subject of relationships. At this point, he admitted he liked me and I said I really liked him.

Then, he tells me "but". He said if he was in a relationship with me, he'd cheat on me, and that's just how it was. He said monogamy is just limiting oneself, and mentioned how he celebrated when his parents divorced. 

He'd been in a couple of long term relationships before me, so it just makes me wonder why I'm not good enough.  I had been having this issue when my ex left me last year, and this just makes it so much worse. He had said at the end of this: "What's wrong? You look hurt!"
Of course I was hurt. I know not everyone has the same idea of relationships, though. I just don't know what to think. 

I liked him so, so much, and I could have seen us having a future.

I apologize for not putting a concise title up, as I don't know what to call this. He was never really 'mine', any way.  I know I'm probably wrong in how I'm feeling (sad, hurt, even betrayed) because I get that people have different outlooks. I get that, really. And that's okay.
<bot>: Guy I had been seeing said how much he liked me, was showing signs of wanting to date me, but then said he'd never be monogamous.*