“She’s a cool girl, no bullshit,” Tom Pecheux told me at the fall Isabel Marant show a few weeks ago. “I’m dabbing a beige Estée Lauder lipstick all around the lips and in the middle, a darker one—still dark nude, but in the center, to give voluptuousness. It’s the French kiss!”

“Wait, that’s a thing?” I asked.

“Well, you know…”

“Like you’ve been making out?”

Then, Marant breezed by and whisked him away. Wait! I wanted to scream, but of course, you’d never do that in front of Isabel Marant. But here’s what I surmised: a French Kiss is a mouth that looks like it’s been made out with. Think of it as the opposite of that infamous, enviable, perfectly painted-on, not-quite-orange-but-just-shy-of-red lip that J.Crew (and a handful of street-style stars) have made famous. The French Kiss is a mouth that is worn-in, or, more precisely, worn off. FROM FRENCH KISSING. Or heavy breathing into a microphone at Coachella. Or, you know, six hours of real life.

In the opposite of real life— backstage at Christian Dior, two hours before Marant’s show—Catherine McNeil was not making out with anyone, but she was enjoying a lollipop while rocking a decidedly French Kiss mouth. Pat McGrath was deep into a multi-part makeup process that utilized fuchsia lipstick, powder, and a helluva lot of tissues, blotting down and building up models’ mouths to achieve a haute-er version of the multidimensional, soft-focus pout that you’d normally be sporting after your lunch break, or that you’d see in your rear-view mirror on the way home from work. It looked lived-in...in that Sky Ferreira, my-lips-have-frostbite way.

So. Let’s say you want to do as the French—or particularly amorous among us—do and say “ Pfft!” to ‘long-wear.’ What to do? Very little! Your choices are: a) Smear on some Ruby Woo in the morning and never look back (literally…go forth, let it deteriorate throughout the day, and feel confident knowing that reapplying your lipstick is so 1957); b) Paint some Benetint in the center of your mouth, extending outwards, for a Prada-esque, wine-stained look; or c) Go the reductionist route: Kate Young, who’s been styling Ferreira lately, was at the Gloffice earlier this week and mused, “Sky always gets it right with the lip.” To demonstrate the technique, she found a mirror, whipped out her trusty Dragon Girl pencil, smeared it on in one big circle with what appeared to be one eye closed, grabbed a tissue, and wiped her mouth clean. “There! That’s it. It just looks…” Wait—let me guess. Like a cool girl, no bullshit? “Totally.”

—Emily Weiss

[1-3] Catherine McNeil photographed by Emily Weiss backstage at Dior Fall 2013 in Paris on March 1, 2013; [4-6] Katya Riabynikina photographed by Emily Weiss backstage at Dior Fall 2013 in Paris on March 1, 2013, [7] Jessica Stam backstage at Prada Fall 2013, [8-9] Sky Ferreira, [10] Courtney Love