Justin Bieber Goes Shirtless—and Almost Pantsless—in Miami

18-year-old shows off his six-pack and ever-broadening shoulders while on the move

The world has watched Justin Bieber grow up—and now it gets to see him fill out.

The 18-year-old ditched his shirt in Miami, giving the paparazzi no choice but to take photos of Bieber's six-pack and increasingly buff arms.

And, because the Biebs is cheeky like that, his pants were slung pretty darn low, putting the top of his boxer-briefs on full display, as well.

While not busy strutting his stuff, Bieber was tweeting a countdown to the release of Believe Acoustic tomorrow (though theoretically he could have been strutting and tweeting simultaneously). 

"Wrote from my heart. hope u like it," he wrote to the Beliebers, who no doubt are psyched to hear the sweet sounds of "Nothing Like Us" and "Yellow Raincoat" cranked up to 11.