The pop singer was giving an exciting show when her top slipped off a bit. Katy didn't actually notice the minor wardrobe malfunction and continued on with her show. In related news, Katy has been on a roll lately and achieved her first No. 1 album on the U.S. pop chart recently. Her third album "Teenage Dream" sold a whopping 192,000 copies this last week according to Nielsen SoundScan. She is also the first woman to achieve this feat since Ke$ha did it back in January.