Kendall Jenner just dished on her sex life -- a rare move for her -- and let’s just say the spicy details left momager Kris Jenner totally gobsmacked!

It all unfolds on "The Kardashians" S7 premiere Thursday ... when Kendall, as the crew was packing up the home she grew up in, casually dropped the bomb that she lost her virginity in her old bedroom ... right in front of Kris. Getty

Kris was floored ... blurting out, "Where the hell was I?!" And honestly, Kris -- fingers crossed you were nowhere near that bedroom when your daughter was getting it on!

Turns out Kendall was bluffing ... she later admitted she actually lost it at the guy’s place. The who and when are still a mystery ... but Kendall’s dating history has definitely boasted some heavy-hitters -- think Harry Styles

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