The 20-year-old model uploaded the image on Wednesday night (4 November) with the caption: "My favourite photo for all 40 mill of you. Genuine happiness… taken by Lil Ky @490tx."
She crossed out the nipple herself, FYI.
Kendall didn't explain why the photo was so special to her or why she was so happy at that moment. Or why she is pulling down her black dress and bra to expose herself. So many questions and so few answers!
Fans clearly like it, though, as it's received more than one million likes in just twelve hours…
Kendall's fast catching up on big sister Kim Kardashian West when it comes to Instagram followers. Kendall has 40.4m, while Kim has 51m.
No doubt Kendall will pick up a few more followers next month thanks to her involvement in the annual Victoria's Secret Fashion Show, which airs in December.
The starlet revealed this week that she'd been booked for the show, calling it a dream come true. She'll walk in the lingerie and sleepwear extravaganza with best friend Gigi Hadid, as well as a string of other famous faces.
All you need to know about Kendall Jenner:
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