Three guys die together in an accident and go to heaven. When they get there, St. Peter says, "We only have one rule here in heaven: don't step on the ducks."
So they enter heaven, and sure enough, there are ducks all over the place. It is almost impossible not to step on a duck, and although they try their best to avoid them, the first guy accidentally steps on one.
St. Peter immediately appears on the scene, accompanied by the ugliest woman the guy ever saw. St. Peter chains them together and says, "Your punishment for stepping on a duck is to spend eternity chained to this ugly woman!"
The next day, the second guy accidentally steps on a duck, and again St. Peter appears, and with him is another extremely ugly woman. He chains them together with the same admonishment: they will be bound for eternity.
The third guy has observed all this and, not wanting to be chained for all eternity to an ugly woman, is very, VERY careful where he steps. He manages to go months without stepping on any ducks, but one day St. Peter comes up to him with the most gorgeous woman he has ever laid eyes on, a very tall, tan, curvaceous, sexy blonde. St. Peter chains them together without saying a word. The guy remarks, "I wonder what I did to deserve being chained to you for all of eternity?"
The woman replies: "I don't know about you, but I stepped on a duck."
(Thomas Cathcart and Daniel Klein, Plato and a Platypus Walk into a Bar, Penguin Books, 2007, pp. 190-191)