I like this one

Brian Hester invited his mother over for dinner. During the course of the
meal, Brian's mother couldn't help but keep noticing how beautiful
Brian's roommate, Stephanie, was. Mrs. Hester had long been Suspicious of a
relationship between Brian and Stephanie, and this had only made her more
curious. Over the course of the evening, while watching the two react, Mrs.
Hester started to wonder if there was more between Brian and Stephanie, than met the eye.

Reading his mom's thoughts, Brian volunteered, "I know what you must be
thinking, but I assure you Stephanie and I are just roommates."
About a week later, Stephanie came to Brian saying, "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?" Brian said, "Well, I doubt it, but I'll send her an e-mail just to be sure."
So he sat down and wrote: Dear Mother, I'm not saying that you "did" take the gravy ladle from the house, I'm not saying that you "did not"take the gravy ladle. But the fact remains that one has been missing ever since you were here for dinner.
Love, Brian


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

I like this one, I think it's cute. That Mrs. Hester is one crafty woman. But I wonder why the author felt it important to give his character in a joke a last name. Just a thought...