Kendall and Kylie Jenner can't keep it together after sharing their most embarrassing moments

When Kendall and Kylie Jenner sat down for an interview with Cosmopolitan recently, we're betting they had no idea what was to come.

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While most of the talk was pretty tame, when the sisters were asked what their most embarrassing moment was, Kendall dobbed Kylie in straight away.

"I know what you're going to say," Kendall said to Kylie before breaking into hysterics.

"I know they're going to use it and I'm just so embarrassed," Kylie replied.

In between giggles, Kendall manged to reveal that Kylie had "pooped her pants" when she was five and failed to make it up the staircase to the bathroom in time.

"She pooped all over the stairs," Kendall said. "And it was all over the carpet. She left a trail of s*?! all over the stairs into her room."

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Luckily, Kylie took it on the chin, shrugging it off and laughing herself. We're betting these two had some words in the car on the way home though!