It's been more than a year since the only male Kardashian sibling became known for his struggles to lose weight. While his sister Khloe has often expressed her love and admiration for him on social media, she finally opened up about Rob's issues while talking to her stepbrother Brody Jenner during a family vacation in Thailand.
"Rob has said, 'Being in that house, it was so dark, and it made me do dark things.' It gets to me, it makes me feel bad," Khloe told Jenner.
"I definitely feel guilty, and I don't care what anyone says," she added. "I was not there to protect Rob, I was not even there to protect myself."
In addition to his weight issues, Rob has been said to have a "very bad drug problem."
In a different scene from Sunday's episode Khloe is seen talking to a friend about how concerned she is for her brother's mental health.