Interestingly, chimps have sexual swellings through 40 percent, roughly, of their menstrual cycle, bonobos 90 percent, and humans are among the only species on the planet where the female is available for sex throughout the menstrual cycle, whether she's menstruating, whether she's post-menopausal, whether she's already pregnant.
性器充盈的时间大约 是月经期间的百分之四十， 而倭黑猩猩约百分之九十， 人类在地球上唯一一种 女性可以在整个月经周期 进行性交的物种， 不管她在经期， 或者经期后， 抑或她已经怀孕。