He wants to get married but im not sure if i even want a relationship....advice please?

.My ex and I have been together for 3 years. We have a little boy who will be 2 on the 22nd of this upcoming month. My ex has the absolute sweetest heart and would do the world for his son but the problem is he cheated on me with two females I know for a fact then had atleast 3 others tell me the same old story of "he made them feel so close as if they were dating but he never made it offical". Only reason they found out about me was one female worked with me and was telling me all about him. I kept my composure and just told him I was done until he could handle a relationship. We still had a friendship (he got to see his son whenever he wanted, give him a hug sometimes and he knew if he ever needed something I was here but as far as the extra benefits I was giving, weren't happening any longer). Well a year later, he wants me back. He came to me and said how point blank "These hoes don't have his back". He wants to be a family now, talking of moving in along with marriage but honestly I'm not sure if I'm ready for it. That's all I've ever wanted from him was commitment to give our child a family unit neither of us had before growing up but I don't want to get played again. Words do not begin to explain how I felt before and never want to get down to that low again....any advice?