A little boy walks into his parents’ room and sees his mum on top of his day bouncing up and down.
They stop and his mum quickly dismounts, pulling the covers around her.
“What were you and dad doing?” the boy asks his mum.
“Well your dad has a big tummy and sometimes I have to get on top of it to help flatten it” she explains.
“Your wasting your time” says the boy.
“When you go shopping the lady next door gets on her knees and blows it right back up.”