Inside the party, which was presented by Bumble, the Jenner girls hung out with Kourtney Kardashian's on-again, off-again boyfriend, Scott Disick. Kylie was all smiles as her big sister's ex wrapped his arms around her while jamming out during an impromptu performance by Post Malone.
Kylie even shared a few Snapchats of the two dancing to the singer's hit, "White Iverson."
The trio was surrounded by A-Listers, including NFL quarterback Johnny Manziel, The Weeknd, Bella Hadid, Miranda Kerr, Ruby Rose, DJ's Martin Garrix and Alessio, and Snapchat CEO, Evan Speigel.
Another notable guest? Scott's rumored 20-year-old girlfriend (and Kendall lookalike!), Christine Burke. Though there were no pics of the two together, the model did share a snap of her and her friend, Charlotte Dalessio.
The star-studded party included a surprise DJ set by the Pizza Boys. While hot tracks were spinning, Kendall and Kylie passed out pizzas on the dance floor. Kendall, 20, even assisted with the music by taking control of the Pizza Boys' laptop!
Kylie also got to play DJ for a while, crashing Simi & Haze's set at a party hosted by Paper magazine later in the day.