Justin Bieber moons fans, followers

It happened quickly.

Justin Bieber shared a shot of his bare cheeks on Saturday on Instagram, mooning anyone who happened to see the photo before he deleted it.

The pop singer, wearing a black tank top, sunglasses and a hat, is looking over his shoulder with a grin, as he pulls his pants down to show his bare backside.

While E! says it was just a prank, it might also have been a way to pull in more social media followers. On Twitter, Bieber is counting down the days to the release of his new "Believe Acoustic" album.

And in other Bieber news, Stacy Betts, who filed a lawsuit against the singer last summer after she attended a concert with her daughter in 2010 that she claims left her with permanent ear damage, has dropped her court case.