Here's where it gets messy. While said ex and I were hanging out at a book store a few days ago, we got into a fight (over something absolutely ridiculous - he later on realized this) and he took me home immediately afterwards. Well, I was feeling completely miserable and felt like there was absolutely nothing left for us (I was just fed up with everything), so I did something unlike me. The next day, I slept with a guy that's been a customer at my job that I met a while back. Half of me feels guilty, half of me feels like I technically didn't do anything wrong since my ex and I are broken up. A few friends have told me that I haven't done anything wrong, but my heart is telling me that I have.
I stopped by my ex's house today to pick up something I let him borrow that I needed back. When I left, we decided that we weren't going to keep contact for a while since it's what needed to happen. Before I left, he told me that if I did anything with another guy, to never talk to him again and to forget ever getting back with him. I told him I thought it was unfair to expect me to act like I'm committed to him when we're not even a couple, but he didn't concur. Being afraid of losing him forever and knowing that what I did a few days ago was blatantly due to the fact that I was angry, hopeless, and hurt, I didn't tell him. He made it seem like he could just completely forget about me and shrug me off like it's nothing if he found out what happened. Doesn't that, in a way, show that he doesn't care as much as he could/should? Is he entitled to know about this? Should I feel guilty for keeping this from him? Should I feel guilty about what I did, despite the fact that we're not together?