Men and women view infidelity differently. The female sexual desire is often tied to her emotions. The male sex drive, on the other hand, is based more on physiological factors than it is on psychological elements.
It’s for this very reason that your self-image takes a nose dive when you find out that your wife had an affair. Relationship betrayal makes you question your self-worth.
Doesn’t she find you attractive anymore? Maybe you’ve become boring. What does the other guy have that you don’t?