Rob Kardashian reportedly didn’t attend big sister Kim’s wedding to Kanye West in Italy on Saturday after a major blowout. The only Kardashian brother has experienced a significant weight gain, and according to X 17, sources said it contributed his skipping out on what some have called the wedding of the century.

The family was supposed to wear Valentino as they left France for Italy, but Rob didn’t fit into that plan. He became upset and reportedly had a huge fight with Kim on Friday.

"Rob booked his flight for Saturday morning and skipped the lunch at Valentino's. He just doesn't seem to feel comfortable or happy around his family at all,” the insider told the news site. “They're all wrapped up in the same pretty world, and he just doesn't fit in."

The “Keeping Up with the Kardashian” cameras supposedly caught all the drama. Rob had been apparently been chauffeured to fat camp a few months ago, which X 17 assumed was meant to get him in better condition for Kim’s wedding.

His sister, 33, purportedly wasn’t happy he didn’t drop any pounds. “Kim was pissed that Rob hadn't made an effort to drop any weight over the past few months,” the source said. “Rob basically thinks Kim cares about him only for his appearance and he said he'd 'make life easier' for her and just leave.”

But it didn’t seem Rob wanted to be there anyway, according to the source. "Rob said he was sickened by Kim and Kanye's display of wealth and clothes and beauty and called it 'superficial bullsh*t.'”

Rob has been virtually silent on Twitter, and though he deleted most of his tweets, reported the star commented on his stocky form May 20.

“First, i don’t believe in rehab or therapy or anything of that sort and second I’m a grown man and will work on myself when i choose,” he supposedly tweeted.

Another message reportedly read: “I’m aware that I’m fat that def aint a surprise to me lol and my only therapy will be in the gym anyways had to say somethingggggggggg.”

Kardashian follows only 10 people on Twitter, mostly his family members, and has 11 tweets that remain on his page.