Prelapsarian sex The paraphernalia of handcuffs, rope and blindfolds used by modern humans during sex inflicts passivity and a removal of freedom of choice upon the restrained one. For some women this physiological process may evoke primal, primitive reflexes and consenting human adults may be able to psychologically simulate something similar to the emotional content of prehistoric animal sex. We separated from ancestral monkeys new and old world some 30m to 40m years ago. Because this sex game is repetitive she has learned through practice possibly with previous boyfriends that it will give her sexual satisfaction. Gengis and his sons and grandsons acquired thousands of women from conquered territories and enslaved them as concubines. You don't say that your girlfriend wants you to restrain her and dominate her during her most fertile time of the month, but this may be the case. But her dominating personality may prevent her from seeing herself as innately sexy or as the cultural stereotype of "feminine". Testosterone levels help to promote sex drive in both males and females, women's sexiness coinciding with their most fertile time. While I'm not complaining at her tastes, I'm not sure I can see the evolutionary benefit … apart from attracting men who are dominant in bed, which, at the risk of doing myself down, seems a dubious sort of goal at best. Western science finally accepted that women experienced orgasms in Three stages were noted, firstly an excitement phase in response to clitoral and vaginal stimulation, secondly a plateau phase where the monkey grunts, calls, makes an open mouthed face and reaches out, and finally a resolution phase, post orgasm, where the female tries to escape. During the first half of the menstrual cycle women's testosterone levels increase. Burton, F D Sexual climax in female Macaca mulatta. She is anything but submissive outside the bedroom, but seems unable to achieve orgasm without being restrained in some way. From DNA data it has been estimated that 13th century Mongol emperor and war lord Gengis Khan has approximately 16 million male descents alive today6.