Little Johnny goes for a long weekend with his unc

Little Johnny goes for a long weekend with his uncle,a wealthy farm owner. 

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

Uncle John, 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 John! The bull is surprising the cows!" 

The adults share a knowing grin. Uncle John 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 screwing the horse!"