Little Johnny runs into his parents room to find his Dad on top of his Mum. He is horrified.
His dad turns around and looks at Johnny...laughs...and tells him to get out.
The next day the Dad hears strange sounds coming from Little Johnny's room.
He goes in and is horrified to find Johnny on top of his Grandma.
Little Johnny turns around and says:
"Not so funny when it's your Mum is it!!