"Little Johhny's damn Christmas" joke

A Little Johnny went to sit on Santa's lap, and Santa asked him what he wanted for Christmas.
Little Johnny answered, "A damn swing set in the backyard."
"Excuse me?" said Santa.
"I want a damn swing set in my backyard," repeated Little Johnny.
Santa said, "You'll have to ask nicer if you want Santa to bring you something. Let's try again. What else do you want?"
Little Johnny answered, "A damn sandbox for the side yard."
"You have to ask politely! One more time. What else do you want for Christmas?"
Little Johnny thought for a minute, then said, "I want a damn trampoline in the front yard."
Santa sighed and set Little Johnny off his lap. "I'm sorry son, I can't give anything to someone who talks like you do. I'm not bringing you anything for Christmas."
Santa then called Johnny's parents over and told them what had happened. They apologized profusely, saying they didn't understand why he talked like that, and they had been trying to break him of the habit with no luck.
"I know how to stop it," Santa said. "Don't get him anything for Christmas. Just get some dog doo. Put a pile of dog doo in the backyard where he wants the swing set, another pile in the side yard where he wants the sandbox, and another pile in the front yard where he wants the trampoline. That will break him of it."
The parents agreed.
Christmas morning the kid heads downstairs to open their presents. Johnny runs out the back door, looks around, and comes back in. He runs out the side door, looks around, and comes back in. He runs out the front door, looks around, and comes back in, looking upset.
"What's wrong, son?" asked his father. "What did Santa bring you?"
Little Johnny answered, "He brought me a damn dog, but I can't find him!"