But the "New Testament" does allow for no-fault divorce. 1 Corinthians 7:11 in the King James Version of the Bible states, "But if she depart, let her remain unmarried, or be reconciled to her husband". The verse continues, "And let not the husband put away his wife".
It also allows for multiple wives....for non-servants. Ministerial servants should be husbands of one wife. 1 Timothy 3:12 in the Bible states, "Let each deacon be the husband of one wife, ruling his children and his own house well". The verse uses the Greek expression mias gynaikos andres, which literally means "one-woman men". This is the same phrase used in 1 Timothy 3:2."
Considering early marriage ceremonies in parts of the middle east was a simple party where people ended the night with "shacking up"(no government license, pastor, etc.), a guy could have multiple wives, and a wife could leave if she chose, it was "no fault" system. Modern day "mistresses" are simply "additional wives" it would seem. I bet the fundamentalist Mormons explain things this way.