Kim Kardashian and Kylie Jenner Trick Kris Into Believing Kourtney Is Poisoning Her

E! released another clip from this Sunday's episode, which as TooFab already shared, will feature a storyline involving Kris Jenner testing her water because she fears it may be poisoning her. Fans will watch the momager compare the health of her drinking water to what comes out of Kourtney Kardashian's faucet, and the new preview shows Kim Kardashian and Kylie Jenner appearing to trick Kris into believing Kourt is the cause of her mysterious illness.

Now, in the new preview, Kim and Kylie call up Kris to tell her that it's her lab partner that did the poisoning.

"Hi Mom, it's me and Kylie. We figured the whole thing out," Kim begins in a phone call. "Kourtney has been the one poisoning you this whole time."

Kris can't believe it. "Stop! No way, I just was with her. Why would she do that?"

Kim tells her mom that since Kourtney has been trying this "all gluten-free, organic drops," she believes that her older sister has been adding these "things" to all of their food.

Kris' daughters struggle to hold in their laughter as their mom calls Kourney "insane."

Looks like there will be more to this mystery we assumed was already wrapped up after Kris' water passed the test. Kardashian Watergate unfolds Sunday night at 9pm on E!