The star shared a screenshot of the convo, dubbing it "BootyTime."
The reality star called it "booty time."
Blac Chyna, of course, shares a child with Tyga, who is dating Rob's sister, Kylie.
The actress tweeted another jab at the Kardashian family a month after insulting Kim Kardashian's nude selfie.
It remains to be seen if his new fiancee, Blac Chyna, will show up, too.
Khloe Kardashian's estranged husband Lamar Odom also appears in the promo for the new season.
An eyewitness tells ET the newly engaged couple seem "really in love."
Rob Kardashian can't stop smiling around fiancee Blac Chyna.
No bad blood here!
Kardashian tells paparazzi how his family reacted to his quickie engagement to Blac Chyna. (VIDEO: X17)
The star says his fiancee is helping him reach his goal of weighing 205 lbs.
Rob took to Instagram on Monday to share the progress he's made in his weight-loss journey and praise his fiancee for her help along the way.
Plus, see Blac Chyna twerk for dollar bills.
Is Kim the first of her family to comment on her little brother's quickie engagement to Blac Chyna?
