In Justin Bieber’s recent video for “All I Want For Christmas is You,†Mariah Carey is cast as a glamorous 41-year-old Santa Claus with plunging cleavage. If that seems like a fairly unconventional portrayal of old Saint Nick … well, Justin admits to AOL Music that he’s never been a big Belieber when it comes to Santa Claus. “My mom always told me there wasn’t a Santa,†says the singer. “This was her logic: She thought if I grew up knowing about Santa then finding out he wasn’t real, that it would be like she was lying to me. And then when she told me about God, I maybe wouldn’t believe her. So she just wanted to be straight-up and honest with me all the time. But I didn’t tell my friends or ruin it for anyone – I was a good kid!†Wait until Bieber finds out that Twitter pal Charlie Sheen isn’t real, either! (He is a Grimm’s fairy tale monster created to frighten network executives and 19-year-old blondes from Malibu.)