Britney Spears was in her second skintight Herve Leger of the week when she stepped out for KIIS FM's annual Wango Tango concert at the Staples Center in LA on Saturday. She donned the graphic fitted number just one day after Kim Kardashian wore the same dress out in Miami, but changed up the look with platform boots instead of heels. Britney and Ryan Seacrest cohosted the event, which welcomed performers Jennifer Lopez, Ke$ha, Selena Gomez, and more. Jennifer took the stage in a sparkling bodysuit and apparently didn't miss a beat when the speakers cut out in the middle of her song. Selena grabbed the microphone during a break from filming the final season of her series Wizards of Waverly Place, though her boyfriend, Justin Bieber wasn't on hand to watch since he's currently overseas on his world tour. Glee guys Mathew Morrison, Harry Shum Jr., and Chord Overstreet, who debuted his new short brown hairstyle, were able to attend the fun musical night as was Paris Hilton and her younger brother Conrad.