Thanks to HarleyGirl for this.

A cop was on his horse waiting to cross the street, when a little girl on her new shiny bike stopped beside him. ‘Nice bike,’ the cop said. ‘Did Santa bring it to you?’ ‘Yes Sir,’ the little girl said, ‘he sure did!’ The cop looked the bike over and handed the girl a $5 ticket for a safety violation. The cop said, ‘Next year, tell Santa to put a reflector light on the back of it!’ The young girl looked up at the cop and said, ‘Nice horse you’ve got there Sir. Did Santa bring it to you?’ Playing along with the girl, he chuckled and answered, ‘Yes, he sure did!’ The little girl looked up at the cop and said, ‘Next year tell Santa; The dick goes underneath the horse, not on top.