"I shared everything from my relationship with Scott. Everything. To where all these people were involved in my relationship, and it was horrible for our relationship," Kourtney yells.
"I would fight for them if they said these were their boundaries, I would stick up for them. So I'm like, why do you not stick up for me?"
If you've missed it, the sisters have been arguing over Kourtney not sharing enough of her personal life on Keeping Up With the Kardashians.
But Kourtney isn't letting up. In a recent clip from an episode of KUWTK, the sisters come head to head after Khloe and Kim follow Kourtney to a mysterious location, wanting to catch her in the act of meeting up with a new lover.
Unfortunately, Kourtney was just at a standard meeting, but her sisters invasion of privacy led her to erupt at them.
"If I have boundaries, respect them. Just because you love to show every single thing..." Kourtney says before Khloe interrupts with, "I don't like to...that's our job."
After the clip aired, Kourtney posted more of their argument on her Instagram story.
Kim is shown speaking to the camera: "Kourt spends a lot of time off-camera. I'll see things that I read about online and wonder 'did this really happen? Is she talking to this person?' And realise that it's true but she's so secretive with us that she won't even tell us."
Kourtney wrote over the clip: "' A lot of time' but filming 5 days a week. Let me live."
The fact that Stephanie has made is clear that she isn't team Kim throws it back to 2017 when Kim let Stephanie go as her assistant.
In 2018, Kim cleared the air on her website.
"You guys, we've never had a feud. [Steph] wanted to go in a different direction. I respect that. I love giving that encouragement to whoever I'm working with. People just took it… just because people stop working together doesn't mean that they're feuding and stop being friends."
Kim, seemingly unbothered, has hit back at Kourtney by posting a photo of her and Khloe on Instagram writing, "My Ace! ♠️" as the caption.
Kim has reportedly been cutting Kourtney "out of the loop for months".
An insider close to the family told Radar Online that Kourtney didn't leave the show because she wanted to, but because Kim forced her out.
"Kourt is accusing Kim of forcing her off the show by belittling and cutting her out of the loop for months if not years now," the friend revealed. "She’s convinced this all started because Kim got jealous that she was losing her divine right to be next in line to her mom, and bit by bit she’s used her influence to undermine Kourtney at every turn."
It also adds to that rumour that the sister's fight as soon as the cameras are turned off, and are apparently unable to "be in the same room as each other".
"Kourtney has hated Kim for a couple of years now. She thinks she’s vapid and mean," an insider told Radar Online in October.
"Their egos have clashed big time and when the cameras aren’t on, they don’t speak. There are hints of their feud, of course, but the reality is they genuinely can’t stand each other.
"Kourtney has much better things to do with her time thank kiss up to Kim," the source continued, adding Kim believes Kourtney "would be nobody without her".