A farmer is giving his wife last-minute instructions before heading to town, to do some chores.

"That fellow from Sematol will be along this afternoon, to inseminate one of the cows.  I've driven a nail by the right stall so you'll know which one I want him to impregnate."

Satisfied that his wife could understand the instructions, the farmer left for town.

That afternoon, the 'Inseminator' arrives, and the wife dutifully takes him out to the barn, and directly to the stall with the nail.

"This is the cow right here," she tells him.

"What's the nail for..??" the guy asks.

Replies the wife, "I guess it's to hang up your pants."