Some traditionalists will state men are the promiscuous sex and women the monogamous one. Blank slatists, feminists or not, will argue there is no real difference but only cultural expectations. Neither are satisfactory imho or correspond with my experience.

In The Selfish Gene Richard Dawkins explains male and female genes have different reproduction strategies, largely promiscuous vs. monogamous, but it is also in their interest to adjust themselves to each other. Using game theory, he concludes (or borrows from somebody else, I forgot) that men are 5/8 monogamous and 3/8 promiscuous, while women are 5/6 monogamous and 1/6 promiscuous. (Whatever that may mean: percentages of the population; the length of some episodes in male and female lives; mixed feelings within individuals; or a mixture of the three.)

And I must say, the figures may not be 100% accurate, but they do make sense to me. It feels exactly like what I've been seeing around me for decades. On the one hand, men can be very much in love with just one woman, within a relationship or just longing for her, so they are by no means simply promiscuous, but very often not purely monogamous either. On the other hand, one can meet lots of women who wouldn't dream of a ONS and would even think it offensive if proposed one, and then all of a sudden one meets a girl who is not only promiscuous, but thinks it the way to be for all women.

So the differences are not as big as sometimes supposed, but still big enough for conflicts and friction all the time; and it is not by accident mostly men pay for casual sex with women and hardly the other way round. Thoughts?