Well, not literally. Mariah Carey may not have actually been sporting Calvin Klein Collection (not body-con enough for you, Mimi?), but the diva showed her support of Francisco Costa and Co. in Brazil this weekend at the first-ever Oi Fashion Rocks event in Rio De Janeiro. Carey belted the tunes while Costa showed his Fall 2009 collection on stage–before he took the stage for himself for a bow and a little rock star treatment of his own.