There's this little boy who was awoken in the middle of the night by strange
noises coming from is parents' bedroom, so he decided to investigate. He
nudged the door slowly forward and as he entered his parents' bedroom,
he was shocked to see his mum and dad shagging for all they were worth.
"Dad! Dad!" he shouted, "What are you doing?"
"It's OK son", replied his father.
"Your mother wants to have another baby, that's all".  The little boy was
immediately excited at the prospect of a new baby brother, was very pleased,
so he went straight back to bed with a smile on his face. Several weeks
later, the little boy was walking past the bathroom and was shocked to
discover his mother was on her knees sucking furiously on his father penis.
"Dad! Dad!", he shouted, "What are you doing now?".
"Son, there's been a slight change in plans", his dad replied.
"Now she wants a Mercedes"