Kardashian Sisters On The Warpath After Caitlyn TRASHES Their Dad

Caitlyn Jenner has gone too far! Radaronline.com has exclusively learned that the Kardashian sisters are banding together against the transgender icon over the fact that she used her new book, The Secrets of My Life, to talk smack about their late father, Robert Kardashian, Sr.

“They feel like Caitlyn had no right to talk about their dead father Robert,” a close pal of the Keeping up with the Kardashians clan told RadarOnline.com. And now they're furious!

“Any relationship that Caitlyn had with Kim, Khloe and Kourtney is going to be completely gone now!” the insider claimed.

As RadarOnline.com previously reported, in The Secrets Of My Life, Jenner discusses the infamous O.J. Simpson murder trial and claims that Robert – who represented Simpson as part of his ‘Dream Team’ – knew that Simpson was guilty of savagely murdering his then ex-wife, Nicole Brown Simpson, as well as her pal, Ronald Goldman.

“I would have been okay with it if they had gotten him in the first trial. The implication was obvious that he believed O.J. was guilty,” Jenner pens in her upcoming biography.

According to Jenner, the reason that Robert chose to represent O.J. was to get back at Kris Jenner for marrying Caitlyn.

“I wonder if it was his way of saying to her what I think she was saying to him when she married me: a big f*** you,” Caitlyn writes.

“The Kardashian girls have a very high tolerance for bull****, but where they draw the line is when anyone talks bad about their dad,” the insider told RadarOnline.com.

“Who does Caitlyn think she is? It’s her own fault that she is no longer on good terms with anyone and that family and then she goes and sells them out to sell copies of her book," the insider huffed.

“This is not going to end well at all."

Do you think that Caitlyn Jenner should have kept her mouth shut and never written the book to begin with? Tell us your thoughts below.