As my dear readers may have noticed, it is very common in my world for women to have multiple sexual partners. In fact, this is not only the case among humans, but among most mammals as well as other classes of animals.
The first reason for this is simple biology. The birth ratio on my world is significantly skewed towards the male in that there are approximately five human males born to every female human. Also, women live significantly longer lives than men. Finally, even in your world, the greater the sexual dimorphism of a species, the likelier it is for the physically dominant gender to be polygamous, and that principle also applies in mine.
The extreme sexual dimorphism in my world means that all human societies are female-dominated, and cultural variations never vary in this regard. In the majority of societies in my world, women may take multiple husbands, and in the ones that are monogamous, women usually keep additional lovers in the house in arrangements similar to concubinage or slavery. Furthermore, women are socialized to be sexually adventurous and promiscuous, and having multiple husbands and lovers is considered a badge of prestige. On the other hand, even in recent times, men are still expected to be chaste and demure in matters of sex and other earthly pleasures, and to defer in these matters to the wishes of women. In this context, it is thus easy to see why it is that what is called a threesome in your world is merely a matter of course in mine.
The first reason for this is simple biology. The birth ratio on my world is significantly skewed towards the male in that there are approximately five human males born to every female human. Also, women live significantly longer lives than men. Finally, even in your world, the greater the sexual dimorphism of a species, the likelier it is for the physically dominant gender to be polygamous, and that principle also applies in mine.
The extreme sexual dimorphism in my world means that all human societies are female-dominated, and cultural variations never vary in this regard. In the majority of societies in my world, women may take multiple husbands, and in the ones that are monogamous, women usually keep additional lovers in the house in arrangements similar to concubinage or slavery. Furthermore, women are socialized to be sexually adventurous and promiscuous, and having multiple husbands and lovers is considered a badge of prestige. On the other hand, even in recent times, men are still expected to be chaste and demure in matters of sex and other earthly pleasures, and to defer in these matters to the wishes of women. In this context, it is thus easy to see why it is that what is called a threesome in your world is merely a matter of course in mine.