Rob Kardashian broke his radio silence on Sunday when he returned to Instagram with an unflattering post about his sister, Kim Kardashian.
The youngest Kardashian sibling posted a screenshot of a bloody Amy Dunne from "Gone Girl" and compared his sister Kim to Rosamund Pike's character from the movie.
"This is my sister kim, the bitch from Gone Girl," he wrote.
The post remains up, but Rob has not posted anything since. It's also not shocking he would write something like that, according those close to him.
"He has a funny sense of humor and posts weird things and then delete them," a source close to the Kardashian family told People. "It's just him."
Other family members, however, are concerned with the Kardashian brother and his behavior, especially when it comes to his weight struggle.
"He's been depressed and just a bit off in general," a source of Rob told People. "But he has always been this way. He just can't lose the weight and he doesn't try - he just sits around."
Rob celebrated his birthday last Tuesday. His sister Kim and Khloe Kardashian both posted birthday wishes to him on their Instagram accounts.
"Happy Birthday to my one and only brother Robbie!!!!" she wrote on March 17. "I love you so much and can't wait to share so many more memories with you!"
Khloe wrote,"Happy birthday @robkardashian!!!!!! Never will I ever meet another man as great as you! I know this is the year where you will find your happiness again! I will be right by your side, holding your hand, every step of the way!!! I adore you my one and only brother!!"