Originally Posted by
GoldfishMan
I think it's more about familiarity than jealousy.
Women are very different from men. To us, familiarity often leads to boredom, infidelity, punting, etc.
Women, on the other hand, are more sexually stimulated by familiarity. They tend to enjoy sex more with a close partner than with a stranger. That is what they found from research.
I guess it might be a subconscious trait as a result of the physical sexual differences between men and women.
Our dicks stick out from our bodies, and we expel our baby-making stuff out of our bodies. Women, on the other hand, have internal sex organs and have to take "external inputs" into their bodies to procreate.
So naturally, women would want to do it with someone they consider to be trustworthy and clean (familiar), but men just go everywhere sticking their dicks into every good looking hole they could find.