Is living with big sister Khloe Kardashian helping Rob Kardashian's confidence and weight loss? The elusive younger brother of the Kardashian sisters has finally returned to social media, posting a shirtless photo to Instagram.

"#tbt Me just chill-zoning in Malibu eating a pulled pork sandwich," Kris Jenner's son captioned the Instagram photo. He is leaning over, showing off his tanned back and tattooed arm, wearing a beanie and tucking into a tasty sandwich at the beach.

A photo posted by ROBERT KARDASHIAN (@robkardashian) on Jul 30, 2015 at 8:58am PDT

According to Us Weekly, Rob Kardashian has been keeping himself out of the public eye to keep away from fat-shaming fans following his recent dramatic weight gain. But now, he's living with Khloe Kardashian and it sounds like it's doing him wonders.

Earlier this week Khloe revealed she's enjoying having her brother live with her in her house while he works through tough times.

"Rob lives with me now, and I wouldn't have it any other way," Khloe told Complex magazine. "I love having him with me. I have a big ass house and I wanted it so he could feel like, comfortable."

"He's going through a hard time now," she admitted. "And [my home is] behind gates. With this crazy lifestyle you have to think of places where you can still have your freedom."

"I call him my son as a joke," she went on. "I'll call my assistant and be like, 'Did you guys ask if he wanted lunch?' or this or that and my sisters hate that I do that. I do baby him but I'm a maternal person," she said.

It's too bad his own mother Kris Jenner doesn't seem willing to reach out and help her son.

As we previously reported, Rob's decision to post a shirtless photo is very uncharacteristic as he goes "to great lengths to cover up his body and wears all black."

"He finally had enough of his own mom fat-shaming him, and he took to Instagram to let the Keeping Up With The Kardashians matriarch and his shallow sisters know that he was done hiding for them," the publication wrote.

Us Weekly reports that Rob has been making a "slow and gradual return to social media" in the last couple of months. He wished Khloe a happy birthday on June 27 and gushed over his niece Penelope Disick in mid-July.