Justin Bieber & Mariah Carey Premiere "All I Want for Christmas Is You" Music Video

Beliebers watching the Christmas in Rockefeller Center special last night were in for a special treat from Justin Bieber! The 17-year-old singer premiered his new music video for "All I Want for Christmas Is You" — with help from Mariah Carey!

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Justin tackled Mariah's high-pitched version of the song in a special duet from his Under the Mistletoe Christmas album.

In a recent interview with Billboard magazine, Justin opened up about his voice getting deeper.

"That was the hardest song to do," Scooter Braun, Justin's manager, explained of "All I Want for Christmas Is You." "A year ago that would have been no problem."

"Yes, that was high," Justin agreed. "But I grinded it out and we got it down."

The video features Mariah dressed in a very sexy Santa costume and Justin in a festive holiday jacket singing inside a department store.

Toward the end of the video, Mariah and Justin finally meet up and sing together inside a sleigh and pass out presents to Beliebers.

What could be any better?

Justin and Mariah holding a puppy! Yes, yes they do.

What do you think of Justin's "All I Want for Christmas Is You" song and video? Is Mariah's Santa costume too sexy?

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Watch the music video, below.