Possible role of menstruation

  When an animal gets angry or fearful or stressed, they respond immediately: they run, kick, scratch, bite or kill. Simple.
    In Leoanard Shalin's talk on his book "Sex Time Power", he mentions how Gyna Sapiens ;) are the only species who menstruate as we do. He also mentions men want sex far more than other species. My theory is this: Men release alot of built up stress through sex. The sexual frustration is a symptom of intellectual and emotional frustration. There's also stress in the whole courting process: will she accept me or won't she. There's anxieties caused by insecurities. Men believe a woman does not love him if she doesn't have sex with him quite often, so he's conquering his own insecurities when she accepts. He thus projects the energy of "I have conquered you" at and into her, which is a stress to her, an assault on her sensibilities. Stress is toxic. Sex is thus toxic. Toxicity is detrimental/damaging and thus a "sin against"/"missing the mark of" well being. Is not his frustration his "not finding a solution" thus "missing a mark"/solution?
   So now we have all those toxins being poured into the woman's reproductive system. It is already scientifically known when a woman is not ovulating, the chemical make-up of her bodily fluids destroy sperm. So, within her reproductive system are toxins from semen, and dead sperm as well as her own body's toxic reaction to the assault of the perception of conquering, all of which could poison her. There is this strange persistent belief amongst men that "blood washes away the sins of men".........
  And honestly, when I am sexually active on a regular basis, I always look forward to the cleansing tide of my monthly flow.
   Amongst the species, ours has a unique purpose for sex which presents a unique problem which delivered a unique solution. Easy, peasy ;)