My ex came back to me a little over a year after he cheated on me. The thing is though he is in IN and I am in NV so that was a problem (or blessing). He just told me that he really had thought about what he had done to me, apologized profusely, and tried to patch everything back up. Eventually I realized that I still didn't trust him. Actually, I knew that he would never cheat on me again, but I couldn't trust him in the other things that he had said he changed on (like cleaning, or not working 16hr days 7 days a week). Plus, the anger at the OW that I thought had gone away was apparently still there and I didn't want it to be and unfortunately just his presence reminded me of it all.
It was so weird too because three weeks before that happened I was finally good and felt like I let go that part of me that wanted him back so bad. Finally able to watch Swingers and get the ending.