ex coming back after I got a new man

I was sitting at mine and my boyfriends house tonight and my ex snapchated me and we were talking before me and my guy got together, but then the ex stopped texting me like he always does and I got tired of it so I moved on and he sent to me tonight he wanted to get back with me. He cheated on me early on in our 2 year controlling relationship I couldn't do anything but I love him. But now that I have a new guy its like he wants to come back into my life and I don't know what to do!!!! Please help