Glenn Martens insists on showing us his underwear. “It’s the most important thing!” he jokes as he hoiks up his gray knit sweater and tugs down the top of his black denim jeans: “Because look!”

Martens is here on the last day of Paris Fashion Week to reveal our first glimpse of something big, exciting, and ready to launch: his new collection with H&M. The Swedish fashion retailer has tapped the Belgian fashion maverick to become its latest designer collaborator. By doing so he joins a pantheon of past H&M co-creators that includes Versace, Balmain, Moschino, Comme des Garçons, and Maison Margiela —where Martens has just presented his debut ready-to-wear show as creative director. “And it all started with Karl Lagerfeld,” says Martens of the company’s first-ever collaboration collection

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