Paris Fashion Week may just be getting underway but Roberto Cavalli has already thrown the biggest fete. After all, when Kylie Minogue sings happy birthday to your empire and Heidi Klum helps cut the cake, you know this party will be hard to top.Dancers from the Crazy Horse cabaret performed for guests including Janet Jackson and billionaire boyfriend Wissam Al Mana, Tyra Banks, Bianca Jagger, Leona Lewis, Aishwarya Rai and Rachel Bilson.