Kris Jenner surprised fans on Sunday when he shared two new photos of her son Rob Kardashian, showing off his incredible weight loss for the first time.
It's also the first time in years that the 33-year-old has posed with his sisters for a photo, which has been later used on social media.
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Rob happily posed next to sister Kourtney
"4 out of 6 #happybirthdaykhloe," the proud mum wrote alongside the first snap, which saw him pose alongside birthday girl Khloe, Kendall and Kylie.
In the second photo, Rob is happily posing alongside his eldest sister Kourtney. "These two cuties @kourtneykardash @robkardashianofficial #robkardashian #happybirthdaykhloe," Kris captioned it.
In both pictures, Rob is dressed in black trousers, a black hoodie and his usual blue cap. It's clear to see that the youngest brother of Kim, Khloe and Kourtney has lost a lot of weight in recent months, something that didn't go unnoticed by his fans, who expressed their happiness at his return.
Kris' only son later shared more pictures of the party on his own Instagram
"Rob looks great," wrote one, whilst another one commented: "Rob is Back best thing on 2020."
A third one remarked: "Rob looks so good... keep it up."
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Shortly after his mum's posts, Rob shared several pictures from Khloe's incredible birthday party, captioning one of him alongside Tristan Thompson and a friend: "Woo back baby."
Last year, Scott Disick and Khloe revealed that Rob had been working out at Kim's house.
"He goes to Kim's, he's worked out for, like, the past five days or so, and he's kicking a**, and I just want Rob to do what's best for him and what makes him happy," Khloe told ET. "And if that makes him happy, then we will all support him."
Last November, Kim also told ET that she and her brother really connected "the past year or two". "He's doing great," she said of Rob, before admitting, "He definitely is more low-key than all of us, and we love that and respect that."
The mom of four added, "We love having [Rob] around. ... He's doing really good."