I have a hard time believing he affaired down. She's 20 years younger, at least 20 pounds lighter, at least 20 centimeters shorter and generally a big ball of sunshine and happiness.
And, almost certainly so screwed up mentally that she'd have an affair with an older man instead of finding someone her own age who she can really relate to. This isn't obvious to the outside world, it is often hidden by a big smile and nice clothes.
Why? Because someone her own age will think, after a while, "hey, I don't want to live my life with this mess" after they get to know her.
Your WS though hadn't gotten that far and was just thinking "wow, she must think I'm awesome" instead of working on his problems and wondering why he finds a woman attractive who he clearly cannot relate to.
My wife was a young and very attractive woman once, she is an older and very attractive woman now. She dated men who were old enough to be her father (she never told me this until after she confessed to her affair). She had the brains, the smile, the clothes, and she met me by chance. I was different, I was younger than her also.
When she had her breakdown, she had her affair with a guy who was older, and quite frankly "dumb" in her own words. You know, I thought there had to be more, that she had to love the guy or something. Seriously, I wouldn't do this. I've had some hot women come on to me over the years, but I don't want to be a cheater.
But this hit out of nowhere.
I'm thinking at the time, "Really, you want to leave me, for a guy who is an idiot."
Years later after I find out there was an affair I'm thinking "Really, you want to leave me, for a guy who is an idiot...and who cheats on his wife?" Man, did I ask questions, upon questions, and felt "there just has to be more".
What was so great about it that made cheating and destroying our family worthwhile?
It must have been fucking awesome. I've never experienced something that incredible.
I've also never been so screwed up mentally that I didn't care about my wife and children.
Yet, that is the man my wife had the affair with, and that is the woman (my wife) the OM had his affair with.
When my wife stopped being that woman, and came back and tried to repair the damage, then she was a better person. I don't know about him, apparently this was not an isolated thing for him.
20 yrs younger, 70lbs lighter, 5 inches shorter with a great tan and perky boobs.
But, a hooker, which makes it just so clear how messed up your spouse was. He was so messed up he had feelings for a hooker and thought they were real.
You are way better than that.