Kendall Jenner Pranks Kim Kardashian West, Says She's Pregnant

— -- On last night's “Kocktails with Khloe," Kendall Jenner pranked sister Kim Kardashian West in a major way. In a video posted online, Kendall called Kim to apparently break some big news to her big sis.

“I was calling you because I wanted to tell you something and I haven’t told anyone yet because I feel like you could help me figure out what I should do. But, I am pregnant,” Kendall said.

Kim's reaction was priceless: "Are you kidding?"

Kendall said "No," while Khloe and others were listening in.

"I didn't know who to tell first," Kendall said. "If I told mom, she would freak out."

Kim actually said she's "not the one to talk to, because I've had the worst experience and I'm so fresh off the worst birthing experience. Today is not the day, because I'd be a little more negative, cause I'm on like 1 hour of sleep."

As Kim vented to Kendall, the others tried to hold back laughs. Kim continued to explain how she's had no sleep. Kendall actually took the phone away from her mouth and shook her head.

"It's so hard," Kim said, as Kendall pretended to cry. "Are you crying?"

Kim offered to come over and bring her kids so Kendall can "babysit." Finally, Khloe broke the news that this was a prank.