While the pic appears to just be a fond memory of one of Kourtney and Rob's many outings together, it raises some concerns, as Khloe Kardashian took to the social media site one day earlier to share a similar post featuring the 28-year-old reality star.
"If only you could see yourself through my eyes!" Khloe, 31, captioned the vintage photo of Rob kissing her on the cheek. "I'll forever be obsessed with you! My one and only! #MyAce."
Khloe has always been a big supporter of Rob -- he currently lives with her at her home in Calabasas, California -- though she admitted in October she's lost her patience with him. Rob has struggled with depression and weight issues for the past two years, and has been keeping a low profile from the public, including the Keeping Up With the Kardashians cameras that constantly follow his famous family, for over a year.
"Rob is such a great guy," Khloe said at the time. "He's charming, charismatic, everything. That's what's so infuriating. I'm like, 'Where is your will to live life? Let's be around people!'"
He's also been quiet on social media, but took to Instagram last week to share a snap of his pup, Pablito, trying to buy sister Kylie Jenner's lip kit, which sold out within seconds. "I guess someone is disappointed they didn't get Kylie’s lipkit," Rob joked. "Don't worry buddy more coming soon!"