Kendall and Kylie Jenner -- Someone's a Liar

Kendall and Kylie Jenner Someone's a Liar

Kendall and Kylie Jenner NEVER flashed phony IDs at the doorman for the 21-and-over club they partied at Tuesday night ... so claim Jenner family sources.

This squarely contradicts the manager of Vignette lounge, who says the girls -- ages 16 and 17 -- ABSOLUTELY presented fake IDs at the door.

The Jenner sources say the doorman recognized the 2 girls ... he knew exactly who they were ... and let them in without asking anything about proof of age.

The Jenner sources also say the girls had no idea the club was 21 and older. The sources could not explain how Scott Disick and Khloe Kardashian -- who escorted Kendall and Kylie into the club -- could possibly have no idea the girls weren't old enough to legally get in.

The sources were also mum on the photo of Kendall and Kylie -- looking wasted as they sat in the back seat of their SUV as they left the club just before 2 AM.

So we gotta ask ...