In a video posted to Poosh's YouTube channel on Saturday, the model joined her older sister and Poosh founder, Kourtney Kardashian, for a boozy game of Truth or Dare. At one point, Kendall, 25, was tasked with texting the Kardashian-Jenner family group chat and announcing that she was engaged. And the reality star -- who is in a relationship with NBA star Devin Booker -- took on the challenge.
"It's believable, so I will do it," Kendall said, before someone handed her their wedding ring off camera. The "KUWTK" star then sent the message of her engagement to her family group text.
"This is amazing," Kourtney replied. "You know Khloe is gonna write a novel."
Only a few seconds later, Kendall received a video call from her sister, Kylie Jenner, who said she didn't believe the engagement news.
"Kendall, you're lying," Kylie said, while Kendall showed off the diamond ring to the camera. "First of all, it doesn't fit you."
Kim Kardashian, like Kylie, called Kendall and said she knew that she was joking.
"You're lying because you're at home!" Kim said and Kourtney told her sister to "keep it going."
After she epically failed to prank Kim and Kylie, Kendall fessed up when her sister Khloe Kardashian called.
"That's so stupid, why would you do that to us?" Khloe asked.
"Well, at least we know you guys will be excited when the day comes," Kourtney told Khloe, to which Kendall added, "I know you guys were so hyped."
Khloe joked that she was "disappointed" that the ring didn't fit Kendall's finger. "I was like, he couldn't have gotten the size right?"
Meanwhile, also during Kendall and Kourtney's game of Truth or Dare, which closed out Poosh's virtual wellness festival, Kourtney dared Khloe to prank their mom, Kris Jenner, by telling her that she's pregnant.
"So I have a scenario," Kendall told Kris over the phone. "I have not gotten my period in a little while and I was supposed to get it like last week and so I kind of got nervous and like randomly took a test and it came back positive. So I took another one and that one also came back positive and I'm literally about to cry."
Kris then shared that she coincidentally had a dream about Kendall getting pregnant the night before.
"That's so weird you just told me this because I dreamed about this last night," she told Kendall on the phone.
After Kris made her comment, Kendall struggled to hold back her laughter. She tried her best to stay committed to the prank, but it continued to hilariously go downhill as Kris seemed to truly believe Kendall was pregnant.
"I'll put on my clothes and get over there," Kris said on the phone as Kendall and Kourtney attempted to stifle their laughter. "I'll tell you, Kendall...you have to do whatever your heart tells you to do. I think it's great news but I'm your mom."
Kendall then finally told Kris it was all a prank.
"Mom, I'm just kidding. Mom, I'm with Kourtney," Kendall said with a laugh, to which Kourtney added, "She's just kidding mom, relax!"
"Oh f----," Kris said. "Oh brother, alright. I'll go put the champagne back on ice."