Little Johnny and Jane are playing in the garden when they start having an
argument about whether boys are better than girls.  After a while Johnny stands
up and pulls down his shorts saying, "Boys are better than girls 'cos you
haven't got one of these!"  Jane looks at him in astonishment as she knows that
she hasn't got one of those between her legs.  She bursts out crying and rushes
inside to her mother.  A little while later she comes back out with a big smile
on her face. "My mum says girls are better than boys," she says.  "No, they're
not," says Johnny pulling down his shorts.  "You haven't got one of these!"
Jane looks at him, then raises her skirt, pulls down her panties and says, "My
mum says that as long as I've got one of these, I can have as many of those as
I want!"