 Open relationships don't work
It is a biological fact that most men will not tolerate an open relationship with a woman. In most couples there is an implicit contract: the man supplies material benefits to the woman and in return she promises to be sexually faithful. The man will be thus assured that any child she bears, and that he therefore supports, contains his genes. This is known as "kin altruism." There is no benefit, from a Darwinian perspective, for a man to raise a child that is not his own. Certainly there are cuckolds, but this is why humans developed such big brains--to detect deception. You could argue that with birth control, this need no longer be an issue, but it takes time for genetic programming to catch up with the external social and technological realities. Think of climbing with a top rope: at least from my experience, knowing that the rope is there does not in any way diminish the knee-jerk, gut-reaction of fear.
The only men for whom open relationships will work are those who possess large genitals (and therefore their sperm can compete effectively with others') who are naturally promiscuous. Most men are not naturally promiscuous because: one we have been conditioned socially to be monogamous for so long. And two, it is likely more advantageous to have few offspring and pour a large amount of resources into their survival.
That being said, times are changing fast. Likely it will soon be a world populated by men with enormous genitals who **** indiscrimitately.  |