In a sneak peek at Sunday's "Keeping Up with the Kardashians," Kim lays into Caitlyn's recent memoir after reading a copy of it before it hit bookstands.
"I read it to be like, I feel like I'm really fair. I was thinking, is mom exaggerating?" Kardashian explained to Kourtney.
"She's so angry at mom for no reason. It was like, 'I didn't speak to my sister because of Kris, I didn't see my kids because of Kris,'" Kim continued. "Like grow up and say 'I didn't call my kids.' And Caitlyn discredits mom, she said I didn't see a dime of my money. She was insinuating mom took her money and pocketed it and had this huge savings!"
The sisters then did their part to give their mother major props for all the hustling she did for the family.
"The part of our lives that people don't ever see is that for a good 10-15 years, when they first moved to Hidden Hills, everyone thought 'Oh my god, we're moving out of Beverly Hills, we've gotta be broke' and borrowing money from grandma," Kim said. "The money wasn't going into mom's pockets."
"They made the money together and even when mom would book appearances, I worked for her and I would hear her phone calls in the office," Kourtney added. "She would hustle to get speeches. She changed Caitlyn's career and she made her have this motivational speaker business."
"Then she said, 'The Kardashians were so upset when their names weren't mentioned in Diane Sawyer, but it was all deliberate,'" an aggravated Kim continued. "'We did research and anytime the word Kardashian was mentioned, people thought they put the word Kardashian with publicity stunt, so we deliberately never put the name in there."
"That sounds pathetic," Kourtney added.
Kim previously spoke out about how the book put a strain on Caitlyn's relationship with the entire family, who believe the tell-all is filled with lies about them.
"My heart breaks for my mom. You know, because I feel like she's been through so much," she said on "The Ellen DeGeneres Show" back in April.
"She's promoting this book and she's saying all these things and I just don't think it's necessary. And I just feel like it's unfair, things aren't truthful."
When DeGeneres asked if Caitlyn was being honest, Kim replied, "No, not with certain things about my mom."
"I mean, I feel like it's taken her a really long time to be honest with herself, so I don't expect her to be honest you know, about my mom now, but it's just so hurtful," she continued. "I wish her all the success in the world, but not at our expense."