Can a guy settle down with a girl he cheated on ?

Sorry, I hope I'm wrong but I think the answer is no. He's just acting the part right now because he has too, but it won't be long before he strays again and she was a complete fool for taking him back. Even if he never cheats again she is going to have that thought on the back of her mind for ever. That's a hell of an environment to bring a child into.