Hint: it's right below his nose. "Come here, have you seen this manhood right here?" longtime manager Scooter Braun jokes in the opening scene, pointing to the peach fuzz mustache Bieber, 19, is growing.
The teaser is part of what appears to be a new series of sneak peeks from Bieber called #FilmFridays.
Hanging out in a kitchen with some pals, JB takes pride in his burgeoning facial hair, saying, "That's how much of a man I am." He then clears his throat and grunts out what immediately became a trending hashtag, #stache.
Mentor Usher also weighs in on Bieber's maturity, saying, "As a 19-year-old Justin is becoming his own man." And that's when Justin offers up a second clue that he's ready to move on from childish things: a big, hot mug of coffee. "Speaking of grown man, I'm drinking coffee right now," he says.
Mom Pattie Mallette also makes a cameo, talking about how hard it is for parents to let go, but that it's also exciting to see their kids maturing. Cut to a shot of Bieber standing behind a kitchen counter and pretending to walk down some steps.
The brief look ends with a single shot of Bieber working the stage in concert as fireworks explode behind him and the screen fades to black with the words "There's more to his story."
The movie, directed by Jon M. Chu (who also was behind Bieber's "Never Say Never" movie), is slated to hit theaters around Christmas. The #stache hashtag joins another tag Bieber recently launched, #MusicMondays, which promises to unleash a new song every week for 10 weeks leading up to the movie's release. The series kicked off last week with the release of the new slow jam, "Heartbreaker," and continued on Monday (October 14) with the R&B grinder "All That Matters."