@justinbieber/ Instagram

Justin Bieber Doesn't Need A 21st Birthday Because He's Been A Man For Years

All the testosterone. All of it.

Justin Bieber turns 21 today -- happy birthday, bud! Your 21st is a milestone birthday, but it's a milestone we at MTV think Bieber's actually already crossed. He's been manly ever since he chopped off those floppy locks, and, hello, that was four years ago -- that's enough time for a baby to be born, grow up and start school.

Here are seven ways Justin Bieber's already crossed into manhood:

  1. He had a mustache.

    Listen, not every dude can grow one. Justin may be one of those dudes, but at least he tried.

  2. He's obsessed with tricked-out cars.
    @justinbieber/ Instagram

    Justin is buds with the guys from West Coast Customs (they not only make him cars, but they had him on their show). Also, cars = testosterone.

  3. He can admit when he's not at his best.
    Getty Images

    Justin apologized for getting off track, recording a heartfelt message for fans while admitting that he's afraid of what people think about him.

  4. He gives to charity.
    Gilbert Carrasquillo/FilmMagic

    It takes a real, caring person to put themselves before others. Any Belieber will tell you Justin's constantly reaching out to those in need.

  5. He poses in his underwear with topless models.
    Calvin Klein

    Remember that Calvin Klein campaign? Of course you do. So manly.

  6. He's already bought and sold a house.
    NCP/Star Max/GC Images

    Not a lot of young people have dealt with real estate -- unless you're Kylie Jenner. But Justin's already bought a place and lived on his own in L.A. (Fun fact: Khloe Kardashian now lives in his former house.)

  7. He has the ability to laugh at himself.
    Comedy Central

    Biebs gets his own roast on Comedy Central on March 30 at 10 p.m. It takes a true man to let comics like Seth Rogen take their best shot at him.