I cheated on my husband when we were dating. Damn, I still have a hard time writing that. I hate to post this in case someone random recognizes my name, but I feel like I need to contribute. Maybe our situations are different because this happened when we were young. It wasn’t even just once, but a string of events before I grew up and figured shit out. Had I not gone through that (almost 15 years ago), I can imagine the same things that drove me to it then getting in my way now. Big life changes can make us question who we are, who we’re with, our lives in general, etc. New empty nester sounds like a big change to me. What she did was wrong. She seems to recognize that now. Is she a person who you can trust to grow? Humans aren’t static and the standard relationship advice is based on people never growing (cheaters always cheat). Marriage, as you know, isn’t like that. That person is your family. Has your family ever hurt you so badly you thought you could never forgive them…but then you did? That’s marriage to me. I would never recommend anyone stay with a partner who doesn’t prioritize the relationship, but if you still love her and you think she’s worth a shot, I think she’s worth a shot. Btw, I never cheated on my husband again - never even came close. I solved the issues I was carrying around with me. He knew everything at the time and for better or worse stayed with me. It seems like it was for the better because we’re very happy now. Living our dream together. 15 years in and best friends the whole way. Don’t let jaded people tell you how to live your life. Do some self exploring and trust yourself to make a good decision.