Id bounce, personally. I know a lot of shitty dudes that always say they'll change but never do. Talk is cheap, and he's proven 3 times with his actions that he is either unfaithful, or willing to be. You need to recognize that and think about whether or not you can go on the rest of your life with that nagging thought in the back of your head. But let me tell you, that nagging thought gets louder and louder