For s few hundred thousand years humans lived in small bands of 40-120 or so. It seems fairly clear to me that from an evolutionary and reproductive point of view that the purpose of concealed ovulation would be for the female to copulate with several of the males to confuse paternity and increase the chances of receiving help in raising the offspring. Also, I assume that the fact that many women are able to have multiple orgasms is an evolutionary development to facilitate multiple copulations. This doesn't take into consideration the social aspect of human sexual behaviour in a group of that nature whereby human beings also copulate purely for pleasure and not merely for reproductive reasons. It is only with the development of settled agrarian societies that the emphasis on controlling female sexuality emerged as the transmission of property rights brought the male to wish to be able to prove paternity. This is breaking down somewhat in modern urban societies which have effectively reintroduced a form of nomadism and where the anonymity of society provides females with far more sexual choice than in a closed agrarian society. Also, since females are also now property holders in their own right, which is actually a very new situation this gives them more freedom of sexual choice. It's an interesting development. I would also say that based on my personal observation of human behaviour that all successful copulations are ultimately initiated by females and that it is female choice that drives human mating behaviour whether for reproduction or for pleasure.