If his wife has done something that he cannot in good conscience live with, fine. But if tall, distinguished-looking Prager has found a younger, hotter honey, then my respect for him goes down to zero.
And what would lead you to jump to such a suggestion so quickly?
It's seldom a true either-or situation. There is a wide range of possibilities besides the two you suggested.
For example, a man can reject a dreadful spouse and at the same time take up with a younger, fit goodlooking woman.
Some people have an almost pathological bias against goodlooking women. Don't hate them 'cause they are beautiful. It's entirely possible for a man to find a very attractive romantic companion that is a woman of substance. I know - I have one in my life right now.
The fact that a man takes up with an attractive woman, in itself, is no reason to cause your respect for him to plummet to zero.