Masturbation, named after the Bible’s Onan who spilled his seed (pulled out and came on the side) when he was commanded to have sex with his dead brother’s wife Tamar in order to knock her up. Contrary to jerking off, Onan was using the withdrawal method of birth control because he did not want to get Tamar pregnant, possibly because if she had a son, the son would have received the inheritance that Onan was counting on getting. (And we think things are complex between William and Harry!) This was a terrible decision on Onan’s part, given how he was then struck dead by God for refusing to impregnate his dead brother’s wife. It may seem a bit harsh of God to kill a dude for pulling out, but it’s how they rolled in the Old Testament.