Justin Bieber's Sweet Backstage Surprise

Justin Bieber is known to go above and beyond for his "beliebers," and the upcoming TLC doc This is Justin Bieber proves the pop star always has time for a fan (or two) in need.

A joker at heart, Bieber gives two teen girls the most surreal Punk'd moment of their lives, surprising them with tickets to a TV appearance/concert in this preview for the upcoming TLC special.

This Wednesday fans will get a behind-the-scenes look at Justin's hectic life, interactions with his UK followers, as well as a few exclusive acoustic performances from his new holiday album, Under the Mistletoe.

Don't miss This is Justin Bieber when it airs tomorrow on TLC.

MORE: Exclusive: On Set for Justin's New Christmas Video