Can a cheating boyfriend be forgiven?

He and I dated for two years; he still is my best friend and regardless if we do become a couple again, I will still always be in his life. I love his family and he loves mine. He was drunk when it happened; the part that bothers me more was that he didn't fess up to me. If he would have I think I would be more forgiving. I know he would not have told me. It makes me sick to think about if he got away with it. The cheating wasn't past heavy kissing. He is extremely remorseful. He is doing everything he can to change himself so we can maybe someday work this out. I told him it's over and there is no point, but he refuses to give up. I know he is a good guy who occasionally does very selfish and stupid things. I just need to know if someday I will ever be able to trust him again. I wouldn't let him know it, but I still want us to work.