Female sexuality in perspective

Wikipedia notes that humans are one of the few species known to have intercourse even when the female is not in estrus (the most fertile period of time in the female’s reproductive cycle).
Intelligent social animals learn that cooperative behaviour can be far more successful than that of any individual alone. Hence the Wikipedia entry concludes that, for humans, the use of sex has evolved beyond reproduction to reinforce strong emotional bonds between sexual partners important in long-term sexual relationships.
So humans have sex for a variety of reasons:
recreational: enjoyment of sexual pleasure;
bonding: emotional intimacy to support longer-term sexual relationships (deferred reproductive); and
reproductive: directly seeking to achieve pregnancy.
Individuals are motivated by each of these to varying degrees. Our social history indicates that men are more likely to benefit from enjoying sexual pleasure. After all, only men are motivated to pay for sex. Whereas women are more likely to benefit from the emotional intimacy that keeps a man motivated to support the family.
Reproduction is the main purpose of sex
With all the hype about sexual pleasure it is easy to forget that the PRIME purpose of sex is to reproduce. This involves not only a man impregnating a woman but also the provision of a PROTECTED environment in which a child can hope to reach maturity.
Even today a woman benefits from having the protection of a strong and capable man. So a woman chooses a man who is likely to be able to protect her and a family against the threat from other human males as well as other dangers. Sex provides an emotional intimacy that makes a relationship more stable and more capable of sustaining children in the future.
If a woman wanted sex the same way that men do, they might be tempted to have sex with many different men even when they have children. But who would support them while they are raising all the resulting children? A man wants to know that a child is his before his is likely to be willing to contribute towards its upkeep.
A human female needs to be able to offer a mate the sexual interaction he needs so that he does not seek sex elsewhere. Now we might think that Nature would ensure this by causing sex to be equally pleasurable for men and women. The fact is that there is no need for this because women already have enough incentive: the survival of themselves and their children.
Kiera Knightley stars in the film ‘The Duchess’ in the title role as the Duchess of Devonshire (1757 – 1806). The story portrays the duchess in a loveless marriage under obligation to provide a male heir for her husband. She falls in love with another man but if she spends her life with him she loses the right to live with her children.
Given the choice between sexual pleasure with the man she loves and her children, she chooses to raise her children. Many men are perplexed when women lose interest in sex once their family is complete. Ultimately, the prime purpose of female sexuality is for a woman is to raise a family.