Man, you are WAY different than I was. I went thru a lot of emotions towards my wife, but "sad" wasn't one of them. "ANGRY" was more the norm.
I was sad for my KIDS, and sad for MYSELF, and even sad for my MARRIAGE, but I sure-as-shootin' wasn't sad for my WIFE that she spread her legs for another man.
Maybe it was all the intel I was seeing and listening to.