It looks like Rob Kardashian knows how to hold a grudge seeing as the "Keeping Up with the Kardashians" star hasn't talked to his sister Kim and Khloé Kardashian since he abruptly left his sibling's wedding festivities without attending the ceremony last month.

According to RadarOnline.com, sources have revealed that the sock mogul "has no reason to talk to Kim," revealing that "they haven't been on good terms for a very long time."

Apparently Kim "hasn't bothered to even attempt to talk to him since returning from her honeymoon, [while] Khloé has sent him text messages and left him several voice mails."

The insider went on to say that "Rob hasn't returned any of Khloé's phone calls or texts. He feels completely estranged from his sisters and family. He really isn't in a good place."

Since making his way back to the states following his departure from the overseas gathering Rob Kardashian "has been holed up in his house, and hasn't been returning calls from concerned family members."

The source said, "Rob made the decision months ago that he didn't want to have a recurring storyline on the upcoming season of 'Keeping Up with the Kardashians,' and drastically cut back on filming."

Kim and Rob Kardashian reportedly got into a heated argument in which Kanye West's wife accused her brother of leaking negative stories about her to the media.

An insider revealed "Kim and Rob haven't been speaking to each other for months - she thinks he is lazy, and bringing down the family name because of his physical appearance."

Sources close to the family have confessed that his mother Kris Jenner is "extremely worried about" her son. "She knows he isn't in a good place, and is encouraging her kids to continue to reach out to Rob."

Do you think it is wise for Rob Kardashian to distance himself away from his famous family? Let us know your thoughts in the comment section below.