A father and his son were looking at a nativity scene in a London gallery. It was Titian's world-famous painting of the scene at Bethlehem.
The boy said, "Dad, why is the baby lying in such a crude cradle in a pile of straw?"
"Well, son," explained the father, "they were poor, and they couldn't afford anything better."
Said the boy, "Then how could they afford to have their picture painted by such an expensive artist?"