Tom married a woman with an identical twin.

Less than a year later, he was in court filing for a divorce.

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

“Well, your honor, every once in a while my sister-in-law would come over for a visit, and

 because she and my wife looked exactly alike, every once in a while I’d end up making love 

to her by mistake,” said Tom.

“Surely there must be some difference between the two women.” the judge said.

“You’d better believe there is a difference, your Honor. That’s why I want the divorce.”