There once were two Irishmen, named Shawn and Pat, who were the best of friends. During one particular night of revelry, the two agreed that when one passed on, the other would take and spill the contents of a bottle of fine, Irish whiskey over the grave of the fondly missed and recently dead friend.
And as fate would have it, Shawn would be the first to pass. Pat, hearing of his friend's illness, came to visit his dear friend one last time. "Shawn," said Pat, "can you hear me?"
Faintly, Shawn replied, "Yes, Paddy, I can." Bashfully, Pat started, "Do you remember our pact, Shawn?"
"Yes, I do Patty," Shawn strained. "And, you'll also remember that I was to pour the contents of a fine, old bottle of whiskey over your grave, which we have been saving for, going on 30 years now?" said Pat.
"Yes Patty, I do," whispered Shawn.
"It's a very "old" bottle now, you know," urged Pat.
"And what are you gettin' at Pat?" asked Shawn, briskly.
"Well Shawn, when I pour the whiskey over your grave, would ya mind if I filter it through my kidneys first?