Three woman always hang their laundry out in the backyard.
When it rains, however the laundry always gets wet.
All the laundry, that is, except for Sophie's.
The other two women wonder why Sophie never has her laundry out on the days that it rains.
So one day they are all out in the backyard putting clothes on the line when one of the women says to Sophie, "Say how come when it rains, your laundry is never out?"
"Well," says Sophie, " when I wake up in the morning, I look over at Saul. If his penis is hanging over his right leg, I know it's going to be a great day, and I can hang out the wash. If his penis is hanging over his left leg, I know it's going to rain, so I don't hang out the wash."
"What if he has an erection?" asks one of the women.
"Honey," says Sophie, "on a day like that, you don't do the laundry!"
