Sexy details like leopard print and sequins prevailed at Roberto Cavalli's 40th anniversary bash at Les Beaux-Arts de Paris last night. Stars and supermodels alike celebrated the designer's four decades of decadent fashion with champagne and treats, while viewing a display of some of Cavalli's most famous vintage gowns. Rachel Bilson wowed in an off-the-shoulder leopard print gown alongside pal Taylor Swift (the pair took in his Spring 2011 show earlier this week in Milan) in a daring black minidress. Kylie Minogue performed "Can't Get You Outta My Head" and "All the Lovers" and Mr. Cavalli himself thanked the well-dressed crowd with the help of Heidi Klum and a 10-foot white and gold cake. Click through the gallery below to see all the stars at the sexy fete.