A blonde named Sue marries a Yorkshire farmer.
One morning, on his way out to check on the cows, the farmer says to Sue, "The insemination man is coming over to impregnate one of our cows today. I drove a nail into the 2 by 4 just above where the cow's stall is in the barn. Please show him where the cow is when he gets here, OK?"
The farmer leaves for the field, and after a while the artificial insemination man arrives and knocks on the front door. "I came to inseminate the cow." he says.
Sue takes him down to the barn. They walk along the row of cows, and when Sue sees the nail, she tells him, "This is the one right here."
The man, assuming he is dealing with an airhead blonde, asks, "Tell me lady, because I'm dying to know, how would YOU know that this is the right cow to be bred?"
"That's simple", she confidently explains, "By the nail that's over its stall".
Laughing rudely at her, the man says, "And what, pray tell, is the nail for"?
The blonde turns to walk away and says sweetly over her shoulder, "I guess it's to hang your pants on."