The 35-year-old reality star sported a tight-fitting sheer red Balmain dress to supermodel Naomi Campbell's book signing of her new coffee table book in Beverly Hills, California, on Thursday night, looking notably slimmer than she has since giving birth to son Saint last December. On Wednesday, Kim revealed she currently weighs 139.6 pounds, less than five pounds away from her pre-baby weight of 135.
Kim fangirled over Naomi at the event, taking selfies with the legendary 45-year-old beauty, and revealing that she got a copy of her book signed for her 2-year-old daughter, North.
"So proud of @iamnaomicampbell on the launch of her new book!" Kim captioned a cute snap of the two on Instagram. "Looking at these collection of images is so inspiring! Thanks for signing a book for North! Love you!!!"
Naomi's book signing was a star-studded event, with Gigi Hadid, Lenny Kravitz, The Weeknd, Sean "Diddy" Combs, Kelly Rowland, Quincy Jones, Ashlee Simpson, and Ashlee's husband, Evan Ross, all in attendance.
Naomi and Lenny seemed particularly close, with the "American Woman" singer kissing Naomi on the shoulder at one point, though multiple sources confirm to ET that the two are just longtime friends.
Later that night, Naomi and Lenny both hit up Gigi's 21st birthday party at celeb hot spot The Nice Guy. Taylor Swift, Kendall and Kylie Jenner, Khloe and Kourtney Kardashian, Hailey Baldwin, Lily Aldridge, Jaden Smith, and Hailee Steinfeld were also in attendance, celebrating Gigi's big day.