Shirtless Justin Bieber parties with diddy at atlanta hotspot

Where in the world is Justin Bieber? If you were hoping the answer would be, "Learning some basic human decency and life skills via an intensive therapy boot camp," prepare to be sorely disappointed. Instead, after headline-making trips to Miami, Panama, Toronto and New Jersey, the private plane-polluting popster, 19, surfaced shirtless on Wednesday at an Atlanta nightclub for a Diddy-hosted Ciroc bash.

Justin posed, mascot-like and with his black Calvin Klein underpants on display (see pic below), amid a crowd of hip-hop heavyweights that included Diddy, Rick Ross, T.I., Jermaine Dupri, Lil Scrappy and Wale. Also in attendance at the Vanquish Lounge event: Chantel Jeffries, the Kim Kardashian doppelganger who was with Bieber on the night of his recent arrest in Miami.

Everyone but the Biebs managed to remain clothed. And given that he's under 21, he supposedly stuck with drinking from a water bottle all night (it's unclear if the yellowish liquid in his bottle actually contained any water, however).

ours later, he posted a photo on Instagram that showed him in the studio with Diddy, Ross, Dupri, Wale and Stalley, who are working on Ross's "Mastermind" album. It's not known if Bieber was there to contribute or just to soak up the atmosphere.

During his Atlanta breather, Bieber also hit the ice with a youth hockey league, worked out (again sans shirt) in a hotel gym and played video games with T-Pain.

Bieber is due in a Miami courtroom on March 3 on charges of driving under the influence, resisting arrest and driving with an invalid license.