Kelly Osbourne knows the secret to “voguing,” telling us, “It’s all about space and hard, structured movement, so that you flow into the music.” Osbourne hosted the W Love Hangover Ball emceed by Ladyfag and featuring “voguing.” (Think Madonna’s smash 1990 video that brought the trend to the masses.) Dance crews (called “houses”) battled it out in outlandish outfits at the ball to benefit amfAR. The barely dressed male and cross-dressing models struck poses in runway walk-offs in categories with names like “Sex Siren” and “Male Magazine Face” in front of judges Fergie and Simon Doonan. Osbourne’s beau, Matthew Mosshart, was seen blowing her a kiss from his seat at the W Union Square and told us he thought she looked “amazing as always.” Karlie Kloss, Jason Wu and Lily Donaldson were spotted sneaking sips from a bottle of vino in their front-row seats. Doonan, who hasn’t imbibed since 1985, recalled he never used to worry about hangovers. “I just thought about getting [bleep]faced,” he said. “Hangovers, shmangovers.”