Present in almost every single human society has been the expectation that females be much more selective in their choice of sexual partners than men. In many of these cases, the expectations for female behavior are actually self-imposed, with other women being the biggest detractors of women who break the sexual norms. There is an evolutionary explanation for this.
Humans and primates and many mammals more broadly can be distinguished from other species on the planet because of the biological demands reproduction places on women. Human infants take a very long time to form in the womb, the process of birth can be very dangerous, and the infants remain completely helpless and then significantly dependent on their parents for a very long period of time.
Human infants are distinguishable from the offspring of many other species in that they require high amounts of paternal investment in order to succeed. (as opposed to turtle offspring who are born alone and swim off to the sea immediately with no parental involvement) Maternal investment is usually assumed as a given, so the distinguishing factor that would impact reproductive results amongst human offspring is high rates of male paternal investment. Those females who mated in such a way as to secure high rates of male paternal investment throughout all of our evolutionary history have dramatically outcompeted those who haven’t, causing genes which increase the likelihood of behaviors that make women acquire a mate who will provide high rates of male paternal investment have spread throughout the species.
Sexual selectivity amongst women is the evolutionary result of this process. The wrong choice of a sexual partner means life or death for a set of genes, and because women are the sexual gatekeepers that burden falls on them. Regnures presents evidence that validates this evolutionary line of thinking. He cites a 2012 study in the American Sociological Review on the amount of pleasure females experienced in different sexual encounters. The overwhelming consensus of the data was that the more sexual experiences with the same partner a woman has had, the higher the chances of orgasm: 11% for a first-time hookup vs. 67% for sex in a relationship lasting more than 6 months. An evolutionary theorist would argue that since it is commitment from a male that increases the chance of successful offspring, it makes sense that the body would reward sexual behavior that increases the likelihood of that. Sex with a committed partner feels better and this should incentivize women to stay with their current partner in order to secure more male paternal investment for her offspring.