One of the best-known designers in the industry is Roberto Cavalli. And when he throws a party, everyone shows up.

Yesterday marked the grand opening of Cavalli’s new store Just Cavalli in New York City. The prestigious boutique has a prestigious address - Fifth Avenue.

Just Cavalli will offer a more affordable collection of the designer’s duds, and it’s targeted to a younger crowd.

And at the opening, stars like Jessica Simpson along with sister Ashlee, Petra Nemcova, Michelle Trachtenberg, and Nicky Hilton swarmed the designer with congratulations. Even J Lo was present to give props to Cavalli.