In US, 'spunk' was a slang term for an orgasm in 1880s.
Some men experience instant feelings of sadness and regret after sex. It is known as "post-coital tristesse".
Lily Allen, Mark Wahlberg and Carrie Underwood have three nipples.
Male lemurs put a plug in their mates after sex so other males can't mate with the her.
The middle finger originated in Ancient Greece as a symbol for anal intercourse.
"Transient Global Amnesia" is the technical term for that feeling of a wiped memory after good sex.
The brain has an "automatic penis maintenance function" to force erections if unused for too long.
Female ducks' vagina contains multiple "dead ends" to help protect them against duck rape.
'Haematodipsia' is a sexual thirst for blood.
Harry Potter and JK Rowling share the same birthday.