Dan married one of a pair of identical twin girls. Less than a year later, he was in court filing for a divorce.
"OK," the judge said, "Tell the court why you want a divorce."
"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 so identical looking, every once in a while I`d end up making love to her by mistake."
"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." he replied.