Kendall Jenner's Nipples Make it to the Big Time

They're baaaaack!!

Kendall Jenner's nipples can now make it anywhere ... because they made it to a New York City high fashion runway Thursday.

18-year-old Kendall flaunted what her mama manages ... in a completely sheer brown top and a wig at the Marc Jacobs fashion show.

It was KJ's NY Fashion Week debut, and immediately after her nipples lit up the event ... Khloe Kardashian gushed on IG, "My baby sister killed it today."

Kim Kardashian also weighed in, saying ... "Proudest sister ever!!!!"

Kendall's goodies were last seen in sheer black.

First black, now brown? Kim and Khloe really are proud.