In secondary school, we always had the rumour that if you blew into a woman's vagina then it would kill her.
It was received with more hilarity than sensibility... though it did mean that future oral sex was delivered with a little less exhalation.
Then, it turns out you can kill a girl by blowing into her minge and middle age dudes creased with laughter again, as if the previous 20 years of maturity never happened.