Gotta love that knee jerk blaming the wife.
Some men are just creeps, and would cheat no matter what. (The same goes for women, but we are talking about a man, here.)
I blame all three of the adults. Most of all Mr. Callahan, then Ms. Diaz. He was pretty much of a cad stepping out on a wife of 20 years. Can't believe she didn't know after over 2 years.