Originally Posted by Njord

Also, I should add this.

As animals, humans are hard-wired in a tribal sort of way. Take lions for example. The male Lion will have a dozen or so Lionesses to mate with, yet no other male in the clan gets to have sex (which means, the lionesses have no one else to fuck)
Humans are hard-wired the same way, which is easy to understand once you think about it.