I was with my boyfriend for about nine months when circumstances forced me to move in with him for a couple of months. At first things were OK, but within a few weeks I noticed a huge change. He didn't come straight home from work to be with me and he always found a reason to spend time with friends. By the time I found a place and began the moving out process, we had hit a full-blown rough patch. I think he was resentful that I was living with him, and I was resentful of the way he took it out on me.
In the end we decided to take a break. Even though it felt like the right decision, I was devastated that it had come to this — we had been such a happy couple. During our break, we talked every once in a while, but we never got intimate. Finally he came back to me, saying that he realized his role in everything and wanted to make things work. Together we decided to rebuild things.
It's been about five months and things have been much better, until last week when a friend confided in me that during the time we were separated, my boyfriend was having sex with his ex-girlfriend. My boyfriend's excuse is that we were "on a break," a la Ross and Rachel from Friends. I see it as emotional cheating; we took time apart to see if we could fix things, not to see if we wanted to meet other people. He claims he really does want to make this work, but now I feel conflicted about who he is. He thinks I'm overreacting, but am I? Should I just forgive him for taking advantage of our break?