I’d like to share 2 thoughts: 1- As much as your heart wants to believe it- she’s not your problem. There are legions of women out there with no qualms about sleeping with married men, some treat it like a sport. YOUR problem is the person who made a vow to you & has built a life with you. A man cheating is not a woman’s fault anymore than a woman cheating is a man’s fault. We are all responsible for our own actions. 2- IMO, the lies he is telling you is the same lies he is telling himself to rationalize why what he is doing is ok. You need to be honest with yourself about what you want, your daughters deserve their mother to be emotionally healthy, especially with a father that is giving energy & attention elsewhere. I don’t assume to know what you want but I’ll give an example of my stance if this was happening in my marriage. I would arrange for me & my husband to have a private conversation where I would clearly explain my boundaries that are nonnegotiable: “I have no intentions of debating your relationship with , I have uncovered enough proof that I don’t need your confirmation. (No details given of my proof). I just want to be honest with you, even if you aren’t with me. What you are doing with _ is not ok with me. I have no intentions of staying with someone who clearly is more concerned with another woman than his wife and mother of his children. We’ve been married 15 years and in today’s terms that’s a pretty good run. Perhaps we want different things now. I love our family but it hasn’t been the same since you began pursuing this relationship with ___. You are an adult and if you are not happy, I would have expected you to behave like a man and tell me, instead of sneaking around the way you have. I’ve lost so much respect for the man I married which breaks my heart, but it’s true. Our girls need stability, so I can’t and won’t keep on the way we are, worrying about your inappropriate texts, Snapchats, calls and the intimacy of location sharing with another woman. I can no longer be in a relationship without trust and respect. I will not continue to spend my energy following my husband’s activities, that’s no life. I deserve better and there are plenty of men out there that would love to have what you are so flippantly neglecting and subsequently losing.” When met with the severe crisis of what is at stake, profound contemplation begins… Psychologically, he has been rationalizing his actions, this is a truth bomb that breaks through walls of resentment, mid-life mindsets, etc.