Rob Kardashian is back on Instagram and looking better than ever!

The former 'Keeping Up With The Kardashians' star debuted a dramatic weight loss after arriving at sister Khloe’s 36th birthday party. Not only does Rob look skinny, but he seems happy!

Woo back baby,” Rob 33, wrote via Instagram. On Sunday, June 28, alongside a photo of himself smiling while posing with Khloé’s friend Savas Oguz and her ex-boyfriend Tristan Thompson, who looked dapper in a pink suit.

In several photos shared by Rob on Instagram, the reality star posed with most of his sisters, including Kendall, Khloe, and Kylie, while inside the party. They partied at the pink theme event hosted at baby sister, Kylie’s house. 

We can’t help but notice that Rob is growing his hair out too! The private reality star was all smiling in a black hoodie, matching sweatpants, black and red Air Jordan 4’s, and a LA Dodgers hat. 

Rob also posed with his big sis Kourtney Kardashian on the way into the bash.

We’re so glad that Rob is back looking happy and healthy!