After her performance, Spears ends her night with a quiet return to her Las Vegas hotel. Plus: J. Lo, Jake & Reese and more

'JUST' JENNIFER

Leave it to Jennifer Lopez to turn the red carpet into her own fashion runway! The singer-actress let it flow in Roberto Cavalli at the opening of the Just Cavalli New York flagship store on Friday, where Jessica Simpson and Mary J. Blige (not pictured) also stopped by.