<human>: 21M and I are now talking of reconciling after an eleven month long period of separation. I moved to his city for college recently. 

We spoke for seven of these eleven month long periods. We'd talk every day. We agreed we loved each other, but that long distance was dumb. We'd see other people if it popped up. He tried and did a little, I never wanted to.

Eventually, he said that he wanted to have NSA sex with other girls. It hurt me. A lot. I decided to cut off contact, just to give us space and reassess. 

I went to visit a friend in some college dorms and I slept with a guy I'm quite familiar with. He was nice to me and I felt lonely. I felt like the long distance guy didn't want me anymore. All of my friends told me I should try it, even my fucking mom said I needed to get over it. So I did it. I had never done anything else (even kissed) someone aside from my long distance guy when we were together before he moved. The sex messed with my head a little, but it helped in other ways.

Fast forward to now. I've moved and long distance guy is no longer long distance. He wants to get back together. Told me he didn't have sex with anyone else when I asked. He didn't ask me. I didn't feel like I could bring it up. I know I can't hide it from him, though. I just don't want to ruin everything.

Please help me figure this out. I can't hide it because I feel so guilty. I know (logically) I didn't do anything wrong, but I still can't help but feel like that is that case. Advice is strongly appreciated.

Can you summarize the given text in a few sentences?
<bot>: Ex and I are in talks of getting back together. How do I tell him I slept with someone else? The guilt is consuming me a little.