A dead body was found floating in the river. The police recovered it, and found a wallet with the body. They found out that the wallet belonged to Mr. Smith. But they still weren't sure if the dead body was of Mr. Smith or not.
So they did some investigation and found out about the twin brothers Mark and Harry, who were very close friends of Mr. Smith. They are summoned. At first the police shows them the wallet, then a wrist watch and asks them if they belonged to Smith. They said yes.
The police further asked them if there was any other detail by which they could 100% verify if the corpse was of Smith or not. The twins presented a weird request.
They wanted to see the ass of the corpse. The police were surprised, but agreed. After having a close look at the ass, they screamed "This is definitely not Smith! Smith had two assholes not one!"
The police inspector asked them, "How is that possible? Did you actually see his ass when he was alive?"
The twins replied in union, "We never actually saw his ass, but everytime we both and Smith went out together, someone or the other would always say: Here comes Mr. Smith with two assholes."