Purity is one of the five moral dimensions made popular by Jonathan Haidt. Those most affected by it have stronger reactions of disgust. Some experiments suggesting that purity drives relationship distance in the digital world may indicate there is some substance to it. (Cite.)
Having little squeamishness, and being a sailor, I wonder if my far-ranging posts drive away acquaintances who are more pure of mind than me? Well, those of pure mind may not want to read this article, about the conflict between future mother and fetus, the anatomy of the placenta, and how contact with the semen of the father-to-be lowers a woman’s risk of subsequent pre-eclampsia. But sometimes there are pearls in the muck of biology:
Yet more evidence for a priming effect of semen came from a 2000 paper by Carin Koelman and colleagues. They discovered that a low incidence of pre-eclampsia was associated with oral sex, especially if semen was swallowed.