[flamesfever]

I think, in general, monogamy lessens the chance for marital breakup, and therefore plays a part in the stability of our culture. However, no doubt some marriages will survive in spite of infidelity, or other arrangements.

I recall one of my high school teachers, who had recently got married with the understanding that either he or his wife could date others if they wished. It wasn't long before they were divorced, and he ended up marrying one of my classmates, and the marriage lasted for life.