Rob Kardashian has been quite active this week on Instagram.

Rob Kardashian Is Going Through A 'Hard Time,' Being Held 'Captive' By Sister Khloe?

Although the former Keeping Up With The Kardashians star has yet to speak of his younger sister Kylie's recent 18th birthday, he did share a cute photo of his niece, North West, and her father, rapper Kanye West.

Where Was Rob Kardashian During Caitlyn Jenner's Big Moment At The ESPYs?

Also this week, Kardashian posted a "RIP" message to Paul Newman, and compared his "mood" to that of a Brad Pitt movie, which featured Pitt on a boat with a brunette woman.

According to the latest report regarding the youngest child of the late Robert Kardashian, Sr., Kardashian is said to be ignoring his family's phone calls and text messages.

“Rob refused to do anything for Kylie’s birthday,” a source close to the family told Radar Online on Tuesday. “He is invited to everything and he refuses to come to anything. He’s just ignoring everyone. His mom, his sisters. He just doesn’t care."

Khloe can’t even “get Rob to leave the house. He just hides out there all the time and doesn’t care if he leaves or even gets dressed," the source continued.  “Rob is really making his sisters and even his mom mad. Kim still think he’s really being selfish and she want him to do things with them, not shut them out completely. They don’t know what to do anymore.”