Working different schedules? That's a recipe for an affair. My husband's first affair occurred when we were doing that. It was after the birth of our second child (10 years ago). I personally don't see it as a valid excuse for an affair (affairs can happen in good marriages too), but I think it can draw couples apart and make them a little easier to fall into.
My guess in your situation is maybe your husband's affair is a combination MLC (since he's at that age), lack of interaction with you due to work schedules and also the demands of a young child. My guess is he does believe he still loves you too, but maybe feels a loss of connection and OW and him formed one based on sharing mutual marital "problems." I'm kind of suprised he has told you as much as he did, but I think maybe it's because he still considers it "friendship," even though it's clearly hitting against and passing that boundry with the pet names (and the secrecy... that's fuel for an affair).
I think your best bet is to be a great listener and try to spend as much friendship time with him as possible. Maybe you can start up some walks. I think he needs an ear and to feel someone is listening to him. That's my guess. Ooops! Gotta run my son has a class right now!!!
There is no arriving, ever. It is all a continual becoming.
