In the past, the blame lay at the feet of the male. They were always the cheats, and always found breaking the sacred rules of matrimony. These days, with technology and all what nots, both sexes are found wanting. Especially women who now cheat on their families with reckless abandon and disregard for consequences.
Perhaps, the age old wedding vows/rules should be revisited and tweaked because it seems apparent that humans are not monogamous by nature.