Momsen stays rosy in a bright skirt – and matching lips – at a bash in N.Y.C. Plus: Maks & Karina, Christina Aguilera, Johnny Depp, Mariah Carey and more

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A NEW TUNE?

Newly minted talk show host Jimmy Fallon flaunts his vocal chops, moonlighting as a singer at Tuesday night's dinner for Topshop. His song choice? The comedian – backed up by Mark Ronson (right) – performed Beyoncé's hit "Single Ladies (Put a Ring on It)" for the crowd.