This holiday season, Justin Bieber will show us all just how much he's grown up when he takes us under the 'Mistletoe' with his warm and fuzzy new single.

"I should be playing in the winter snow, but I'm gonna be under the mistletoe," the 'Baby' singer starts, portraying a vastly different kid from the pint-sized, swoop-haired version that we first met in 2009.

Throughout the track, Bieber makes a list of things he knows he should be doing, but admits that he just can't break away from the hot-and-heavy makeout session. Selena Gomez must have one heck of a kiss!

Mid-song, the Biebs really breaks it down, giving a shout to three famous dudes who visited Jesus in the manger. "The wisemen followed a star / The way I followed my heart / And it led me to a miracle / Don't you buy me nothing / Cause I am feeling one thing: Your lips on my lips / Such a merry, merry Christmas," he sings in the bridge.

At 17, the Biebs is officially a man, and despite losing his squeaky clean voice, he's proving song by song that he can still hold tight to the top of the charts -- starting with 'Mistletoe.' We love this track and think it perfectly sets the mood for a cozy night in front of the fire, snow falling outside the window, snuggled up to a loved one (even if it's not Bieber himself).

There's no question which album will be the best seller -- and stocking stuffer -- this holiday season.

Listen to Justin Bieber, 'Mistletoe'