People magazine has new details about Britney Spears’ practical birthday joke on her brother Bryan, who turned 27 on Monday (April 19). After Bryan dealt with the ‘FBI’ and was greeting with a “surprise!” by partygoers, go-go dancers entertained and guests snacked on crabcakes. Bryan was surprised yet again when Carmen Electra and her racy Pussycat dolls took the stage at 9 P.M. for a 20-minute set. Bryan “loved it — he was in shock,” says a partygoer. Then Spears came on to sing ‘Happy Birthday’ acapella in the Pussycat Dolls costume of a bra, panties, corset, and fishnet stockings.