Looking good, Kylie Jenner.
The 18-year-old showed off her curvaceous figure at Rihanna's Diamond Ball on Thursday — and she rocked an outfit that would give Kim Kardashian (and her butt) a run for her money!
Kylie kept her long, dark hair in loose waves and her makeup light.
We bet her 26-year-old boyfriend, Tyga, was pleased with the look!
Scroll through to see more of the famous family members' ass-ets.