Should I take him back?

I broke up with my boyfriend about 2 months ago. It was just one of those little break ups. we started hanging out again, getting back together and such about 1 month after the break up. until I heard he had gotten drunk at a party and that he did stuff with another girl (his sister’s friend) I was devastated. I didn’t hear this from him, but from his friend that was at the party. So, I asked him about it, pretending I didn’t know to check his honesty. All he did was laugh at the question. This however made me feel worse about the situation. So i finally told him I knew, and I told him how it made me feel, he said that he was truly sorry and his last intention was hurting me. He did however pull the “I was drunk” card. I told him being drunk was no excuse. And he said the only thing that would make him happy is me. I don’t know if this is just an act? And I’m not sure if I am over reacting because we were in fact “broken up” ? but it still hurts all the same. Should I take him back? I honestly can’t move on. I’m stuck on him.