Identical Twins

Dan married one of a pair of identical twins. Less then a year later he was in court filing for a 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, sometimes I'd end up making love to her by mistake''

``Surely there must be some difference between the two women,'' the judge said