asks his mother her age
She replies, "Gentlemen
don't ask ladies
Johnny then asks his mother how much she weighs.
Again his mother replies, "Gentlemen don't ask ladies that question."
The boy then asks, "Why did Daddy leave you?"
To this, the mother says, "You shouldn't ask that," and sends him to his room.
On the way, Johnny trips over his mother's purse. When he picks it up, her driver's license falls out.
Johnny runs back into the room. "I know all about you now. You are 36 years old, weigh 127 pounds and Daddy left you because you got an 'F' in sex!"