Yeah Yeah Yeahs Karen O. nip slip & Nick Zinner's Rock Band fail

Karen O (L) and Nick Zinner (R) of the Yeah Yeah Yeahs perform at the KROQ Weenie Roast Y Fiesta 2009 at Verizon Wireless Amphitheater on May 16, 2009 in Irvine, California.
Karen O (L) and Nick Zinner (R) of the Yeah Yeah Yeahs perform at the KROQ Weenie Roast Y Fiesta 2009 at Verizon Wireless Amphitheater on May 16, 2009 in Irvine, California. Photo credit (Photo by Noel Vasquez/Getty Images)

The Yeah Yeah Yeahs are headlining the Just Like Heaven festival, and they joined Klein & Ally to help reveal the lineup.

Karen O. is ready to reveal some crazy outfits! But, what happened when Karen O had a nip slip in front of her brother onstage? And Nick Zinner reveled that he was apparently not good at "Maps" on Rock Band

Featured Image Photo Credit: (Photo by Matt Cowan/Getty Images)