Justin Bieber Proves He's a Man by Growing a "#Stache" & Drinking Coffee in Believe Sneak Peek

Singer tweeted a clip from his upcoming movie for #FilmFridays

Justin Bieber has grown.

The 19-year-old pop star has been getting ripped and showing off his bulging biceps, along with cruising the streets in extra-fancy cars, but those things aren't what make Biebs a man. According to the singer and his manager Scooter Braun, it's all about his facial hair.

In honor of #FilmFridays (to go with #MusicMondays), Bieber released a funny sneak peek clip titled "#Stache" from of his upcoming Believe movie.

"Speaking of grown men, I'm drinking coffee right now," J.B. joked in the video.

"I keep my promises. U got #heartbreaker to #1 so I owe u #filmfridays ....," Bieber tweeted. "Here is your first #filmfridays . The #stache lol - http://youtu.be/GodZdq5AHHQ  see u Sunday at Midnight."

His mentor, Usher, said, "As a 19-year-old, Justin is now becoming his own man." Meanwhile, Bieber's mom, Pattie Mallette, added, "I think it's hard for parents to let go, but I think that it's really exciting, too, to see him maturing."

And that's when the pop star faked going down a flight of stairs behind a countertop (LOL!).

Believe hits theaters Christmas Day.