下一个问题：校艺术团乐队的主唱/首席/鼓手等等，会不会在台上一笔一划地数拍子？

其实更重要的问题是，从 evolutionary biology 的角度：

Why human sex take so long?

Why women prefer even longer sex?

Why human thrusting during sex, which obviously absolutely unnecessary for fertilization, and could hurt female if not lubricated well? (那种说是 push out semen 的理论就算了，日本百人斩电影看多了)。

Why women prefer thrusting, given the fact that women’s clitoris lies outside vagina, which evolved to avoid being directly stimulated by thrusting?

还有更多的问题:

Why we have non-religious music?

Why music beat mimics sex thrusting pattern of 九浅一深?

And why women love "fluid" beats in music? Could that connect to that women hate "jack-hammer" "mechanic" thrusting during sex?

哇塞，

你翻译的真叫一个传神！

感觉XXOO 立马高大上了许多。

今天晚上就推荐给我家的。

唯一的遗憾是，我家的床没有办法承受女上位，会发出很大的吱呀吱呀声。

MD,过两天换个怎么跳都不响的床！！

一个合理的猜测解释：结合 human female 的 concealed ovulation；以及可能的 concealed female extended sexuality；外加 clitoris lies outside vagina, purposely avoiding directly stimulated by thrusting。那么从进化啪啪学的角度，合理推测，是 human female 在 promote longer sex with better thrusting，而不是 human male 。

进一步合理猜测，human female prefer even longer sex with high quality thrusting 的进化动力和进化优势，在于 human child bearing 的 high cost。

而两个臭皮匠，远超一个猪哥亮，是人类养娃进化里不用争论的优势。其他的不论，轮流三班倒这一条就完胜了。

不过对于 human male 而言，sperms 永远是 expendables。滥交的数量优势，是最最简单的进化优势。

而对于 human female，因为 eggs 的先天的稀缺性，pregnancy 十月怀胎的 high cost，不可能是 expendables。所以 human female 没有任何用数量赢过质量的可能性。

这样 human female 必须有跟滥交男抗衡的手段， 才能让质量赢过数量，最终在进化竞争中脱颖而出。

而从这个角度，prefer longer sex（榨干他！），prefer high quality thrusting（只榨优质 highly intelligent w/ good physical 男），self lubricate（耕不坏的田），clitoris outside vagina which cannot directly stimulated by thrusting（确保先累坏耕牛，而不是先累坏田），concealed ovulation（不许用偷看邻桌考卷的方式作弊），concealed female extended sexuality（你猜你猜你再猜，只榨 high intelligent 男），，，都可能就是抗衡滥交男的手段。

什么意思？ 除了人类，其他mammal性交不需要抽查的？

应该不是所有的 mammal 都抽插那么久。

https://www.insidescience.org/news/research-suggests-dolphins-clitorises-are-human-clitorises-better-placed

Female dolphins, like human women, are blessed with sensitive clitorises that engorge with blood, according to a new study. But unlike the human version, a dolphin's clitoris appears perfectly placed for stimulation during intercourse.