You can never make him reform, it is up to him and how much you mean to him. Just resolve to take care of yourself. If you beg him or act jealous and angry he will go. If you take care of yourself and keep your dignity, you will show him you value who you are, with him or without him. We fall in love with people we look up to and admire, people who make us feel better about ourselves when we are with them. If you act as though you deserve to be admired you will get your needs met, if he can meet them. If you beg, act jealous, or desperate and angry, those are not admirable qualities, and he is sure to see you in a less than admirable light.. My advise would be to say you love him and want this relationship, but then ask him to go figure out if he wants it too, or not. Tell him you can't help him decide if he wants, you and your child or someone else. Tell him to go away for a time to think and give him a month to figure it out. If he returns to stay, never ask him what he did that month. Instead ask him to prove he wants to work through the problems by attending counseling together. Men who cheat elsewhere often stay with their wife as a habit, only away from home, can they make a real decision. Habits are broken in 2 weeks. A month will give him and you time to see if being together is what you both decide you want. Loving someone and staying faithful is a concious decision. Do not let the term "just friends" fool you, We do not have to explain our friends. Its more like "just interested" until it becomes more, or until they decide if that person if better than what they already have. Men rarely leave unless and until they have someone else waiting in the wings.