Rob, 27, first posted a screen grab of his big sister in skin-tight workout pants that showed off her voluptuous booty. "#WCW @khloekardashian shneeeeee meeeee claaaaaa," Kris Jenner's son wrote of his sibling.
Khloe, 30, who found his tweet amusing, responded to it via Instagram. "Totally a normal brother/sister relationship," she wrote alongside a screen grab of Rob's tweet. "Incest is best!!! #HeyBooHey."
This is nothing out of the ordinary for Rob, who oftentimes jokes about his "baby mama" and frequently posts updates about his famous family on Twitter. Amongst his three older sisters Kourtney, Kim, and Khloe, and two half-sisters Kendall and Kylie, Rob still remains closest with Khloe.
As reported last month by Us Weekly, Rob is currently living with Khloe in her recently purchased six-bedroom Calabasas, Calif. home. While Khloe was filming her spin-off series, Kourtney and Khloe Take the Hamptons, her younger brother took on the task of overseeing construction of the house.
Khloe told Us in August that Rob was "so excited" to live with her again.
Like her brother, Khloe has also expressed her love for Rob on social media. In August, Khloe posted a sweet throwback photo on Instagram and wrote: "I'll never let you carry more than you can hold my sweet brother."
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