Victoria's Secret Fashion Show: Rihanna, Bieber and a $2.5M bra Rihanna, Justin Bieber and Bruno Mars perform at Victoria's Secret fashion show in New York, while some of the world's top models strut down the runway. November 8, 2012, 10:56 a.m. Who says Justin Bieber isn't the luckiest 18-year-old in the world? He's coming down from performing at the annual Victoria's Secret Fashion Show on Wednesday, where his set was merely part of an event heavily laden with gorgeous "angels" parading around in winged lingerie ensembles. "that was a great rehearsal. #VSFashionShow:)," he tweeted Tuesday, adding the hashtag, "#notcomplaining." Not surprisingly, he said on the red carpet that the show was like a good dream come true. Also in the lineup, in addition to Bruno Mars, was Rihanna, who on the red carpet shared her plans to "torque an extra hip," suck in her "extra stomach" - really? - and arch her back a little more to compete with the models who'd be with her as she performed. PHOTOS: Victoria's Secret Fashion Show Riri even shared a backstage photo or two, giving an idea of the size of some of these runway glamazons. But the real star of the evening? It wasn't exactly Alessandra Ambrosio, the supermodel you see near the end of the video above with the orchid-petal wings. Rather, it was her bra. Ambrosio was the one tapped to wear 2012 VS' fantasy bra, a little undergarment worth $2.5 million. Made by London Jewelers and encrusted with more than 5,000 sapphires, rubies, diamonds and other stones, it features a 20-carat diamond as a centerpiece. Yes, there's a matching belt. No, the bra's not comfortable, Alessandro told ABC News. But get this: Ambrosio just had a baby boy in May. Heidi Klum did the VS runway just five weeks after a baby, but not so scantily clad. The Victoria's Secret Fashion Show airs Dec. 4 on CBS. Kathy Ireland to Kate Upton: Have a plan, bring home the bucks Hey, Heidi Klum! You said you wouldn't walk the Victoria's Secret runway! Is Victoria's Secret model Candice Swanepoel skinny enough to lose her contract? Poll