He lost his top right front tooth. You might notice that the permanant tooth is already half-way in. Damon doesn't pull his teeth out. He let's them come out on they're own. That's how much he hates pain. Or maybe his lame Tooth Fairy doesn't give him enough incentive.]
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Tooth Fairy: "How much to we pay for teeth? Fifty cents?"
Assitant: "I don't know. Should we give him a dollar?"
Tooth Fairy, after checking wallets: "We don't have a dollar."
Assistant: "I saw one in the other room."
Tooth Fairy: "That's his dollar. Your parents sent it to him."
Assistant: "So? He won't know the difference."
Tooth Fairy: "You want to give him his own dollar for his tooth."
Assistant: "Yeah. Why not?"
Tooth Fairy: "Well...we'll pay him back, so I guess it doesn't matter..."
Assitant: "Why would we pay him back? He'll never know."
He was kidding. Of course we'll pay him back. As soon as we get a dollar.