One morning little Johnny woke up and wandered into his parents'
room, and was surprised to see his mum and dad having sex, with
his mum on top, bouncing up and down.
"Mummy, why are you jumping on Daddy?" he asked.
The mum replied slyly, "Well daddy is getting fat, so I am
trying to deflate him."
Johnny said, "Ohhh! Well you're wasting your time. After you
leave for work, the woman next door comes over and blows
Daddy back up."