It's Kendall and Kylie Jenner!
Did you guess Kendall and Kylie Jenner? Then you guessed right! Kendall, 17, and Kylie, 15, dressed up in their big brother Rob Kardashian's sweats and tweeted out the pic. "I think your clothes fit us @robkardashian," wrote Kylie. The two budding models are used to being dolled up, whether it's on their family's reality show Keeping Up With the Kardashians or on the runway for designers such as Sherri Hill. They looked absolutely gorgeous at Sherri Hill's fashion show in September, pictured at left.
It just goes to show: Whether in sweats or party dresses, these teen beauties look great in anything!