Substitute
Little Johnny's teacher was asking all the kids in the class what their parents did for a living.
Little Mary got up and said "my Dad is a pilot, and my Mommy is an architect."
"Great," said the teacher.
Michael got up and said " my Dad is a Doctor, and my Mom is a housewife."
"Good," said the teacher.
Johnny was last in the class and when he got up he said: "My Mommy, she is a substitute."
Knowing better about his background and always striving to correct the kids, the teacher said, "you mean she is a
Prostitute."
"No," Said Johnny, "my Sister, she is the Prostitute, but when it's that time of the month, my Mommy substitutes."