Rob Kardashian is reportedly furious with his sister Kim after a joke she made about him in her recent Rolling Stone interview, according to Us Weekly.

Kim Kardashian West posed as a sexy sailor on the cover of the latest issue of Rolling Stone. During her interview, she was asked about her brother's disappearance from the spotlight in 2013 after putting on weight, reported Us Weekly.

"It's not that mysterious, what's happening with Rob," Kardashian told Rolling Stone. "He has gained weight. He feels uncomfortable being on the show, and that's OK. Do I think he smokes weed, drinks beer, hangs out and plays video games with his friends all day long? Yes."

Mrs. West continued to talk smack about her brother after the interviewer asked if Rob might be experimenting with harder drugs like meth. "No no. Or he'd be skinny," joked the reality TV star, according to Us Weekly.

After Rob found out what Kim said in Rolling Stone, a source told Us that he blocked his sister's number on his phone because he's angry and doesn't want to hear what she has to say.

"Rob and Kim had been cool again and were getting along," the source told Us Weekly exclusively. "Now he's furious at her again for her comments to Rolling Stone. He was been bitching her out on her phone. He's mad—pissed as hell."