Wise mom

Mom comes to visit her son kevin for dinner... who lives with a girl room mate natasha.
During the course of the meal, his mother couldn't help but notice how pretty kevin's, room mate was. She had long been suspicious of a relationship between the two, and this had 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 Kevin and his room mate than met the eye.
Reading his mom's thoughts, Kevin volunteered, "I know what you must be thinking, but I assure you, Natasha and I are JUST room mates."
About a week later, Natasha came to Kevin saying,
"Ever since your mother came to dinner, I've been unable to find the green plate. You don't suppose she took it, do you?"
"Well, I doubt it, but I'll email her, just to be sure."
So he sat down on his computer, and wrote :

"Dear Mother, I'm not saying that you 'did' take the green plate from my house, I'm not saying that you 'did not' take the green plate. But the fact remains that it has been missing ever since you were here for dinner.
Love, Kevin."

Several days later, Kevin received an email from his Mother which read :

"Dear Son, I'm not saying that you 'do' sleep with Natasha, and I'm not saying that you 'do not' sleep with Natasha. But the fact remains that if she was sleeping in her OWN bed, she would have found the green plate by now.
Love, Mom. "

Lesson of the day
Don't Lie to Your Mother