The cowboy position.
 

Two cowboys are out in the range talking about their
favorite sex positions and one says, "I think I enjoy the
Rodeo Position the best."

"I never heard of that one," says the other cowboy. "What is it?"

"Well, it's when you get your gal down on all fours, and you mount her from behind, and you reach around and cup each of her boobies in your hands, and then you whisper in her ear,
`Boy, these feel a lot smaller than your sister's.' And
then you try to hold on for eight seconds."

that's funny

hah. the way i heard it was, he whispers ' damn, your the fattest chic, I have ever fucked before.'

both ways are funny.