One evening, as Uncle Fred and his wife are entertaining guests with cocktails, they are interrupted by an out-of-breath Little Johnny who shouts out, "Uncle Fred! Come Quick! The bull is fucking the cow!"

Uncle Fred, highly embarrassed, takes young Johnny aside and explains that a certain amount of decorum is required.

"You should have said, 'The bull is surprising the cow' - not some filth picked up in the playground," he says.

A few days later, Johnny comes in again as his aunt and uncle are entertaining.

"Uncle Fred! The bull is surprising the cows!"

The adults share a knowing grin.

Uncle Fred says, "Thank you Johnny, but surely you meant to say the cow, not cows. A bull cannot 'surprise' more than one cow at a time, you know..."

"Yes, he can!" replies his obstinate nephew. "He's fucking the horse!