You Have to Draw the Line Somewhere
After their car broke down on a lonely country road, three men sought a night's shelter at a farmhouse. The farmer, poor but eager to help them, said that he only had two beds so one of the three would have to sleep in the barn.
Immediately, one of the travelers, a polite Hindu mathematician, agreed and left for the barn. A short while later he returned and apologetically explained that there were cows in the barn and for religious reasons he could not sleep there.
Another of the guests, a conservative rabbi, volunteered, picked up his bedding and left for the barn. It wasn't long before he returned complaining that the pig in the barn made it impossible for him to sleep there.
The last of the stranded trio, a lawyer, sighed, grudgingly picked up his bag, and shuffled off to the barn. Soon, there was another knock at the door. When the farmer answered it, there were the cows and the pig.