Justin Bieber lost his clothes at his birthday celebration

Delirious paps snapped photos of a half-naked Justin Bieber on Thursday morning as the singer made the odd decision to leave a performance at Birmingham's National Indoor Arena with barely any clothes on.

Bieber was naked from the waist up, and wore athletic-style pants that were pulled down to the singer's thighs, affording a clear view of his white boxer-briefs.

Was he hot? It was in the chilly 30s in England that night.

Bieber returned to his hotel in his half-dressed state. He re-emerged about 3 a.m. (!) to party some more, and didn't wind up coming back until 6:30 in the morning.

"The 'Beauty and the Beat' singer rang in his birthday with his new rumored gal pal, British singer Ella-Paige Roberts-Clarke — and many other gorgeous girls — at the members-only British Luxury Club," reports the New York Daily News.

After a couple of hours in the club, Bieber and his entourage left to get some late-night/early morning grub on Edgeware Road in London, which has a heavily Middle Eastern population. The Bieber crowd got some Lebanese food and finally made it home just when most people were getting up to go to work.

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Sounds like quite a birthday celebration!

But Bieber isn't done partying, oh, no. Today, the Daily News reports, the pop star will throw himself a birthday party at London's Cirque Du Soir, an upscale nightclub with a circus sideshow theme.

Tonight's party will include clowns, fire-eaters, aerial acts, and um, a source told the U.K. Mirror, goblins.

Goblins? Oh yes, the old circus goblins.

Whatever, Justin, just keep your shirt on. He's gone off the rails a bit post-Selena Gomez, huh?

Image courtesy Will Alexander/WENN.com