My ex and I broke up in April and it was a bad break up. I said some really hurtful things bc I was hurting and wanted him to hurt as badly as me at the time. He blocked me on everything. Over the summer, I reached out to him wanting to be civil bc we have a lot of the same friends at school. he said that we could be and then unblocked my number and we started texting again. He was saying we should hook up when we got back to school and be friends with benefits. Although I found out like a week later he was saying all of this while he had a new girlfriend (already). I freaked out and told him he is disgusting for basically cheating on her and then he blocked me on everything again. When we finally got back to school, I heard from his roommates that he talks about me all the time and was saying mean things about me, so I messaged him again saying that I want to be civil and for him to stop. He was short with me, but said we could. Then he messaged me a couple weeks later saying he wanted to be friends and I said no, that I would be civil not friends. then 2 weeks ago my friend went up to him at a party and we all started talking. he asked if he could talk to my friend alone for a couple minutes. my friend told me that he said he still cares about me and wants me to be happy, but it hurts that I say mean stuff about him and I made him really upset over the summer. I messaged him the next day asking if we could talk. I apologized for everything and we started texting again. he said he misses how things were and wants to make me happy. Since then he has been texting me everyday and we have been talking about hooking up, even though he still has a girlfriend. He told me he can't break up with her tho. We hooked up last weekend and he is still talking to me, but said I can't tell anyone about us hooking up bc his girlfriend can't find out. Why won't he break up with her if he is willing to cheat on her? Does he really care about her if he has been texting me and hooking up with me?