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 Mom 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 Aunt, she is the Prostitute, but when she does not feel well, my Mom substitutes."