Then Kim-as-Kourtney, who's sat scrolling her phone across the room, digs back: ''I'm just here on my phone, using the mom card every second."
And she continues: "Khloe used to be my favourite, but she's so far up Kim's *** that I'm just pushing my way through life by myself."
The family had all decided to dress up as each other for the finale episode, with Kendall pulling off an impressive impersonation of her younger sister Kylie, as she mocked her over her lip fillers.
Meanwhile Khloe pulled off the most savage impersonation of all, taking off her mum, Kris Jenner.
Taking on the momager role, she said to Kylie (who was really Kendall in disguise): "Kylie you can sit next to me, because you are my favourite and you make a billion dollars.
"I have my Kylie, my billion dollar baby. Now she will always be the dearest to my heart for a billion reasons," she deadpanned.
In a seperate trailer for the reality show's finale, Kim and Kourtney vow to put the past behind them and focus on mending their fractured relationship.
The conversation between the pair began when the Kar-Jenner matriarch asked her daughters to discuss what they'd like to change about in the coming year.
“I want each one of you to pick one person sitting here and tell them what’s the one thing you’d love to focus on strengthening in your relationship," Kris told her family.
Not surprisingly, the KKW Beauty CEO directed her attention to Kourtney, admitting she's well aware she's often nasty to her.
“I want to fix, you know, my relationship probably with Kourtney, for those mean reasons and those mean comments... I mean, I can be so mean,” said Kim, who shares four children with her rapper husband, Kanye West.
Khloe then pointed out that the Poosh founder is equally to blame, admitting they often butt heads for no apparent reason.
"You guys go back and forth though, It's equal," she said, adding she'd also like to better her relationship with Kourt. "I feel like Kourtney and I sometimes fizzle. So, I think I would love to get us back on course and maybe not be so reactive. For myself."