A source close to the formerly reclusive 28-year-old member of the Kardashian family tells ET that he's "lost another 10 pounds and has really been taking care of himself."
"It really all is because of Blac Chyna," the source adds. "Chyna is great... She has brought this new side of him out, the old Rob! He’s really having a lot of fun."
Meanwhile, Rob appeared in a new Instagram video with Khloe Kardashian's ex, French Montana, on Monday, where Rob is smiling and laughing with the Moroccan rapper.
WATCH: Rob Kardashian Posts NSFW Message About Dropping His Family for Blac Chyna
Last month, a newly single Khloe hit an L.A. strip club with French, whom she dated on and off in 2014, after separating from her estranged husband, Lamar Odom.
Meanwhile, Rob seemingly called out the complicated relationship between his girlfriend, Blac Chyna, and his family last week, in an NSFW Instagram post.
WATCH: Khloe Kardashian Goes to Strip Club With Ex French Montana After Revealing Her Online Dating Profile
"When the p**y so good but your family don't like her," the message says. "So you drop your family and become an orphan."
Ohhh, Rob. What a journey this has been.
WATCH: Blac Chyna Fires Back at Boyfriend Rob Kardashian's Haters -- You Won't 'Run Him Back In'
Despite the apparent call-out, Kris Jenner recently bought Rob a new place to live, and it's pretty nice!
Check it out in the video below.