I think the latest statistics show that 60% of American wives cheat on their husbands at some point during their marriage.
Why do they do it? Well, because they want to and because they can. Studies on infidelity show that wives get caught only 14% of the time, while husbands get nailed about 75% of the time.
There are too many reasons that men and women use to justify their walk on the wild side, so there is not enough room to discuss that here. I just want to make it clear that regardless of the justification that is used, there is no valid excuse for infidelity.
We were all taught at a young age that "two wrongs does not make it right" and this principle is just as valid when we become adults.