A young woman went to an evening class to improve her sexual capabilities. When she gets there, she sees an apple, an orange and a pear hanging on strings from the ceiling, and a piece of chalk and a black-board. "What is all this for?" she asked.

The instructor tells her to stand between the hanging fruit, and she does. "Now," said the instructor, "swing your hips to the left and touch the apple, now swing your hips to the right and touch the pear, then swing your hips forward and touch the orange." The young woman starts to rotate her hips, and soon gets a good rhythm going. "This is great," she said enthusiastically "but what is the chalk for?"

"When you've got the hang of the fruit," said the instructor, "I want you to stick the chalk up your ass and write `Mississippi' on the black-board twenty times."