John invited his mother over for dinner. During the
meal, his mother couldn't help noticing how beautiful
John's roommate Julie was.  She had long been spicious
of a relationship between John and his roommate, and
this only made her more curious.  Over the course of
the evening, while watching the two interact, she
started to wonder if here was more between John and
the roommate than met the eye.
Reading his mom's thoughts, John volunteered, "I know
what you must be thinking, but I assure you, Julie and
I are just roommates."
About a week later, Julie came to John and said, "Ever
since your mother came to dinner, I can't find the
beautiful silver gravy ladle.  You don't suppose she
took it,do you?" John said,"Well, I doubt it, but I'll
write her a letter just to be sure."
So he sat down and wrote:
  Dear Mother,
  I'm not saying you 'did' take the gravy
  ladle from my house, and I'm not saying you 'did not'
  take a gravy ladle. But the fact remains that one has
  been missing ever since you were here for dinner.
  Love, John.

Several days later, John received a letter from his
mother which read:
  Dear John,
  I'm not saying that you 'do' sleep with Julie, and I'm
  not saying that you 'do not' sleep with Julie. But the
  fact remains that if she was sleeping in her own bed,
  she would have found the gravy ladle by now.
  Love, Mom.