Honi soit qui mal y pense
It is enough to make most parents blush with embarrassment.
Britain's most popular nursery rhymes, recited by generations of parents to their children, are teeming with references to bed-hopping royals and teenage sex, according to a book on the origins of 24 playground ditties.
While Jack and Jill may seem innocuous enough in their attempt to fetch water, they are in fact preoccupied with losing their virginity, says Chris Roberts, a social historian who has traced the adult stories behind the nursery rhymes. Jill possibly becomes pregnant and there are regrets later.
"The interesting bit is that, having successfully 'lost his crown', it's Jack who runs off rapidly - probably to tell his mates what happened," said Mr Roberts, 37, author of Heavy Words Lightly Thrown.
In an alternative second verse, the sexual association of the rhyme becomes more blatant. Instead of his head, Jack has a different part of his anatomy patched up with vinegar and brown paper.
The rhyme "Goosey, goosey gander, where do you wander? Upstairs and downstairs and in my lady's chamber" can be read as alluding to the spread of venereal disease - known as "goose bumps" because of the swelling.
It also tackles a row between Henry VIII and the Catholic Church, which owned the land upon which brothels were operating and profited hugely.
Mr Roberts, a librarian at East London University, said his book came out of research he undertook for a series of walking tours around London.
While people already know that Ring a Ring o' Roses refers to the rash displayed by sufferers at the time of the Great Plague, it is less well known that Oranges and Lemons, a guide to the City of London, doubles as a lewd wedding song, he said.
The line "here comes a candle to light you to bed", for example, is an apparent reference to the bride tempting her new bridegroom, while "here comes a chopper to chop off your head" alludes to the woman losing her virginity, or "maiden head"......