Dan married one of a pair of identical twins. Less then a
year later he was in court filing for divorce.

"Tell the court why you want a divorce," the judge said.

"Well, Your Honor," Dan started, "every once in a while my
sister-in-law would come over for a visit, and because she
and my wife are identical twins, sometimes I'd end up making
love to her by mistake."

"Surely there must be some difference between the two
women," the judge said.

"Exactly, Your Honor. That's why I want the divorce."