"The kiss was with a kid I had THE biggest crush on," Kendall Jenner revealed on her website and app
Credit: David Crotty/PatrickMcMullan.com/AP

Kendall Jenner sure knows how to kiss and tell!

In a post on her website and app this Wednesday, the 20-year-old model spills the beans about her very first kiss – and of all places, it happened in the shower!

But before you get ahead of yourself, the reality star turned supermodel assures fans “it wasn’t what you’d think.”

“I was with one of my friends from elementary school, Jessica – this was probably fifth grade,” she explains. “The kiss was with a kid I had THE biggest crush on – shout out to Chad Wilcox!”

According to Jenner, she and Jessica “crushed on him for so long” and were “obsessed” – so naturally, the two friends invited Chad “over to hang out” at Kris Jenner‘s house for a game of Truth or Dare.

“Of course, the point of that was to kiss each other,” Kendall reveals, before going on to explain that since her little sister Kylie Jenner “was so nosy,” they were prompted to explore more “secret places.”

“Kylie kept spying and … we were like, ‘Go away!’ and she was like, ‘What are you doing?!?’ ” Kendall recalls. “She followed us to the living room, then the bedroom. We even locked her out with a chair under the doorknob and she found her way in. So annoying. She kept saying, ‘You’re being shady!’ ”

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To escape her little sis’ prying eyes, Kendall says the three “ended up in my bathroom because it was the only room with a lock.”

“Finally, we got to the Truth or Dare kissing. Jessica and I didn’t want to do it in front of each other so Chad and I went in the shower behind the curtain. And that’s how the magic of my first kiss went down!” Kendall wrote.

Kendall isn’t the only Kardashian/Jenner to recently spill the details about a hookup: Kylie, now 18, explained how her first kiss went down (and called the guy out of the blue!) in a video on her website and app in September, and Khloé Kardashian, 31, revealed she had a one-night stand in Australia back in 2007.