Personally, I think that's a good thing. He might have been sneaky, but now he wants to be exclusive and committed to you. When I was first dating my boyfriend, we were not exclusive and were allowed to see other people. A few months later he said he didn't want to see anyone else and that he loved me and wanted to be with only me. Now he lives with me a year and a half later. Things just work out like that. I say give him a chance.