"Garage" joke

A little boy and girl where sitting in the sand pit naked. The little girl looks down at the boy and points to his penis and says "What's that?".
"I don't know" says the little boy. He to looks down at the little girl and asks "What's that?"
"I don't know." Says the little girl.
They both went home later on and the little girl says to her mum. "Mummy, what's this?"
The mother replies, "That's your pink garage, and no red Ferrari is allowed to park in there."
The little boy gets home and goes up to his dad and says, "Daddy, what's this?"
The father replies "Why that's your red Ferrari and you can park it in as many pink garage's as you feel like."
The next day the little girl and boy were playing in the sand pit naked again and the little girl ask the little boy "What's that?"
And the little boy says "This is my red Ferrari and I can park it in as many pink garages as I feel like." The little boy then asks the little girl.
"What's that?" and the little girl replies "This is my pink garage and no red Ferrari's are allowed to park in here."
Later on the little girl went home and her mother was shocked when she saw blood all over her hands.
"What happened?" asked her mum.
The little girl replied "A red Ferrari tried to park in my pink garage so I pulled it's back wheels off."