Ashlee Simpson (in Roberto Cavalli) and Minka Kelly (in J Brand) struck a pose at the opening of Marquee at The Star in Sydney. "Ladies night at @MarqueeSydney with @Minkakelly @k8herrera @lolozelman. It's gonna be a fun night!! #marqueeSydney," Simpson Tweeted. Click through the gallery to see Carrie Underwood, Brooklyn Decker and more stars at last weekend's hottest parties.