King Arthur was in Merlin's laboratory where the good wizard was showing him his newest invention. It was a chastity belt, except it had a rather large round hole in the most obvious place.
"This is no good, Merlin!" King Arthur exclaimed, "Look at the opening. How is this supposed to protect m'lady, the Queen?"
"Ah, sire, just observe," said Merlin. He then inserted an old wand in the gaping aperture of the chastity belt whereupon a small guillotine blade came down and cut it neatly in two.
"Merlin, you are a genius!" said the grateful monarch, "Now I can leave, knowing that my Queen is fully protected." After putting Guinevere in the device, King Arthur then set out upon his Quest. Several years passed until he returned to Camelot.
Immediately he assembled all of his knights in the courtyard and had them drop their trousers for an informal 'short arm' inspection. Sure enough, each and every one of them was either amputated or damaged in some way. All of them, except Sir Galahad.
"Sir Galahad," exclaimed King Arthur, "My one and only true knight! Only you among all the nobles have been true to me. What is it in my power to grant you? Name it and it is yours!"
But, alas, Sir Galahad was speechless.
