The thing about emotions is they make us tired and yet keep us awake too. And often what happens with a couple is instead of talking and figuring out how to navigate, they tend to toss emotions back and forth. That's what a marriage counselor is supposed to help a couple sort through.

I don't think your husband really wants to leave you either, I think he loves you but he is at a stage in his life and experiencing challenges in his family and even at work where he is stuck and doesn't know how to navigate it all. So he ran home to his parents and talks to some woman who is willing to listen and offer sympathy of some kind. He doesn't want her he wants that from you. As a couple, you drifted apart and it happens when we get so busy trying to deal with family and meeting the expenses of having that family.

Often what happens is as one sees their child in their late teens having freedom to fly, they remember how that felt, yet notice how they don't have that but instead are like that bus driver, driving the same route day in and day out, til he got tired of that and one day just drove that bus for miles and miles, just to experience a change.