Lost gravy ladle
John invited his mother over for dinner. During the meal, his mother couldn't help noticing how handsome John's roommate was. She had long been suspicious of John's sexual orientation and this only made her more curious.
Over the course of the evening, while watching the two interact, she started to wonder if there 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, Mark and I are just roommates."
About a week later, Mark came to John and said, "Ever since your mother came to dinner, I've been unable to 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 a 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."
Several days later, John received a letter from his mother which read, "Dear Son, I'm not saying that you 'do' sleep with Mark, and I'm not saying that you 'do not' sleep with Mark. But the fact remains that if he was sleeping in his own bed, he would have found the gravy ladle by now. Love, Mom"