During lunch at friend/designer Valentino's chateau, Kim allegedly wanted the departure from Paris (to Florence) to resemble a catwalk, with each family member donning a fancy Valentino couture outfit.
But Rob took issue with that proposal.
"Rob said he was sickened by Kim and Kanye's display of wealth and clothes and beauty and called it 'superficial bullsh*t,'" the source states, adding that "Kim was pissed Rob hadn't made an effort to drop any weight over the past few months."
So Rob, believing "Kim cares about him only for his appearance," reportedly replide that he would "make life easier" for his sibling and leave altogether.
Which is exactly what he did!
"He just doesn't seem to feel comfortable or happy around his family at all. They're all wrapped up in the same pretty world and he just doesn't fit in," X17 concludes.
It's been a familiar refrain for Rob, especially since Khloe split from Lamar Odom and he lost a good friend.
The Internet now waits to see more Kim Kardashian wedding photos to see if the family addresses the small detail that the brother of the bride is absent from them.