Justin Bieber shows off his new mustache (sort of) on Instagram.

Justin Bieber shows off his new mustache (sort of) on Instagram.

Justin Bieber still has a long way to go on his journey from boy to man, judging by his efforts to grow a mustache. Yes, he definitely has one, but it’s as thin and wispy as his slender build. Maybe he can train it to lift weights?

The Biebs, 19, has been pumping iron in an attempt to man up his body into a human dynamo with somewhat better results, although he’s spark some speculation that he may be dabbling in steroids.

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The good news is Justin isn’t taking the whole thing too seriously, according to a new 30-second teaser for his upcoming “Believe” 3D movie. The clip opens with manager Scooter Braun gently chiding him about his new man-growth.

“Come here, have you seen this manhood right here?” the longtime manager says, pointing to his upper lip.

“That’s how much of a man I am,” Justin shoots back with a wry smile, before floating a social media tag “#stache.”

Still, the Biebs doesn’t want to totally mock his the fact that he is growing. He leaves it up to his mentor Usher to make the point.

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“As a 19-year-old Justin is becoming his own man,” the R&B crooner says.

“Speaking of grown man, I’m drinking coffee right now,” he adds with a big grin as the camera cuts back to him.

Mom Pattie Mallette also takes a stab putting Justin’s growth in perspective. “I think it’s hard for a parent to let go, but it’s really exciting, too, to see him maturing,” she says.

But don’t worry Bieber isn’t about to become grown up overnight. As soon as the camera cuts back to him, he pulls a goofy sight gag, standing behind a counter and pretending to walk down stairs.

Check out the video below and follow TheImproper on Twitter for the latest Justin Bieber news you can trust.

Footnote: His new movie is expected to hit theaters over the Christmas holidays.