According to Daily Mail, the fashion figure's birthday party (he turned 29 last month, but was in the midst of Paris Fashion Week then) featured Kim and Kourtney Kardashian, and Kris (with Corey Gamble), Kendall, and Kylie Jenner.
A very pregnant Kim wowed in a sheer black sheath with a gold statement necklace, while Kourtney played the part of sweater girl.
It was 18-year-old Kylie's peek-a-boo white net dress — which clung to her figure like a second skin — that seemed to grab the most attention.
Along with the "Keeping Up with the Kardashians" brood, Rousteing's guest list included Mary J. Blige; Jada Pinkett Smith with her kids Jaden and Willow; Jennifer Lopez & Casper Smart; Justin Timberlake & Jessica Biel; Cara Delevingne; and Kate Hudson. Nick Jonas was nowhere to be found.
Thanks to the Kardashians' affection for social media, we almost feel like we were there!