Watch: Kim Kardashian Frames Kourtney For Poisoning Their Mom!

During the upcoming episode of KUWTK, Kim Kardashian and Kylie Jenner team up to throw Kourtney under the bus and prank a paranoid and extremely gullible Kris Jenner. Watch the clip above to see what goes down! 

After their health-conscious mother began a quest to undercover the root of her mysterious illness and to find out who’s been “poisoning” her, the sisters saw their opening.

"Oh my God, we have to f— with mom," said the scheming duo.

Once the Kardashian-Jenner matriarch answers her phone, Kim wastes no time laying the trap. "It's me and Kylie. We figured the whole thing out,” she said.

Then the 37-year-old unloaded the fake bombshell. “Kourtney has been poisoning you this whole time!”

A horrified Kris exclaimed, "Stop. No way! I just was with her. Why would she do that?”

"Just because she's, you know, has been trying these new all gluten-free organic drops and we think that she's been adding these things to our food," Kim answered, laying it on thick and totally fooling poor Kris in the process.

Keeping Up With the Kardashians airs Sundays at 9 p.m. on E!

Watch the clip above and let us know what you think of the hilarious prank in the comments!