A couple decide they quite want to try anal sex, but the woman decides to play it safe and seek medical advice first. "Anal sex is perfectly safe," says her doctor, "as long as you take it slowly at first and use plenty of lubricant. And you take care not to get pregnant, of course." "What?" says the woman incredulously, "You can get pregnant from anal sex?" "Certainly," replies the doc, "where did you think scousers came from?"