So I'll try to make this really short. My boyfriend and I have been dating for 2years. A few weeks ago he ask if I was cheat I said no. From then he would always bring it telling me I'm lying to him (I didn't cheat on him). So he said we need some time apart I was like fine whatever. 3days later he told me he knew the true that I did cheat on him and it was OK. Now I know this is were I messed I was just pissed I said fine I did it and he was like I know. 5mins later I told him it was out angry and if he didn't believe me I would even take a lie detector test for him. He said fine to that then he told me slept with his ex the 3days we were on a break and that it was OK we both did it there is no need for the lie test. So I don't know if be just telling me he slept with just to get back at me because I know for a fact this girl would have called me and raved about it to me. I'm just confused

That sounds like a really fun relationship. Why would you want to be in that with so much drama? It is possible that this wasn't the only time he was with his ex. It is possible that the break was planned so that he wouldn't feel guilty about sleeping with his ex. Regardless, move on... He sounds like a real piece of work.

LOL! What are you even doing with this guy? How old are both of you? This sounds like a complete mess of a relationship. The guy is a jerk and you play right into his behavior.

Most likely he was cheating, before, since a good sign of someone cheating, is they start blaming the other one