If you were to rely primarily on Google and Instagram to form your opinion of Leslie Cohen Amon, chances are you’d start out with the wrong impression. Her online footprint includes the website for her successful swimwear line, Leslie Amon, which affirms that she and her friends can generally be found “on the cliffs of Il Pellicano or lounging poolside at Cala di Volpe.” Sprinkled around the Web are photos of Amon engaging in various forms of jet-set idleness with Giambattista Valli and other BFFs. In one shot, Amon is riding a white horse under a series of giant crystal chandeliers while surrounded by a group of people dressed as 18th-century French courtiers. It was taken during her 2017 wedding reception—at the Château de Versailles.

Okay, the image of Amon as a glam, privileged party girl isn’t entirely false: She did grow up in elite precincts of Geneva and has passed many summer afternoons on yachts anchored off Ibiza. But spend a bit of time hanging with her at her new Paris apartment and you’ll see that she’s more complicated, and more interesting, than her online persona suggests. Nerdy and intense and irrepressibly eccentric, Amon still exudes clear traces of the rebellious, purple-haired art student she once was. Her favorite adjective, it seems, is “weird,” and it’s one that she applies frequently to herself. Since launching her swimwear business in 2017, she has discovered her inner workaholic and now spends long hours stressing about balance sheets and cash flow strategies. And in her spare time, she’s been obsessively decorating the Paris place, where the mix of objects is as eye-catching and unpredictable as she is. On a living room wall there’s a painting by George Condo that was a group wedding gift from friends; it depicts a naked, bug-eyed woman pleasuring herself with one hand while holding up a phone with the other. What is she doing? “She’s taking a picture!” Amon says, laughing. “Of you!”

Scheurich and Carstens Keramik vases, in the dining room.

Photograph by Hugues Laurent; Styled by Gianluca Longo.

An Eric Croes lamp and assorted mineral pieces.

Photograph by Hugues Laurent; Styled by Gianluca Longo.

In design and fashion as well as in life, Amon says, she’s always had a taste for the sensual, the extravagant, and what she calls the dérangeant (French for “disturbing”). She was a shy 8-year-old when she discovered her parents’ hidden copy of Sex, the 1992 Madonna photo book shot by Steven Meisel, and promptly snuck it into her room. “It was really erotic and scandalous—my first taste of a fashion story,” she remembers. A few years later, while the popular girls at her Geneva private school were ignoring her, Amon was at home drawing comics and becoming increasingly obsessed with fashion; at 13, she created an entire scrapbook as a tribute to Karl Lagerfeld’s work for Chanel. (“I mean, bizarre, non?”) After high school, her conservative parents pushed her toward a business career, but Amon was rejected everywhere she applied. Then, on Twitter, she befriended a Filipino woman who’d graduated from London’s ultracompetitive Central Saint Martins fashion school, and with her guidance Amon assembled a portfolio, submitted it, and was accepted. (Even Amon’s mother finally approved, since she’d read in Madame Figaro that Central Saint ­Martins is the top art-and-design school in the world.) Paris internships followed at Valli, Lanvin, and the hatmaker Maison Michel.

George Condo’s Dreaming Woman, 2007, which Amon’s friends gave her as a wedding gift, hangs in the living room, near two vintage chairs.

Photograph by Hugues Laurent; Styled by Gianluca Longo.

Amon’s line of bathing suits is the result of another choice that seemed odd a few years ago when her fellow classmates were taking jobs with the big fashion houses or launching their own ready-to-wear brands. “Few people were doing swimwear then—I thought it was a good niche,” she says. During London Fashion Week, Amon notes, there’s a reason why you tend to see so many Central Saint Martins grads showing “all those crazy designs, and they last for, like, two years, and then you just forget about them. Because at school they didn’t teach us things like, Who’s going to wear your clothes?” In Amon’s case, the target clients were the girls in her social circle, who during their summer holidays often found themselves going straight from a late beachside lunch to a boat to a nightclub while still in wet bikinis—“and looking gross,” she says. What if their swimwear were chic and well-made enough that they didn’t need to change? She started with a ­collection of six pieces, each named after one of her friends, and tweaked the designs based on their feedback. The styles tend to be very fitted and made of top-quality, quick-drying materials with exactly the right percentage of Lycra. Rule number one: “Any loose fabric, people will hate!” Amon says. The concept was a hit, and by year two Amon was selling in places like Bergdorf Goodman, in New York, and Browns, in London. This year, she delivered her first shipment to Net-a-Porter and launched a resort collection.

Amon wears a Fabiana Filippi jumpsuit; vintage jewelry from Karry Gallery, Paris; and Christian Louboutin boots in the wallpapered TV room.

Photograph by Hugues Laurent; Styled by Gianluca Longo.

Amon still spends much of the year in Geneva, where her husband, Ronen Chichportich, works in the diamond industry, though they both feel at home in the high-ceilinged Paris flat they bought last year. She says the idea of hiring a decorator never occurred to her. “I think I like design even more than fashion,” she says, citing influences such as Renzo Mongiardino, Madeleine Castaing, and Studio Peregalli. The one-bedroom apartment is in a classic Haussmann-era building in the 7th arrondissement, making it an ideal setting for Amon’s blend of elegant and dérangeant. On one wall, framed by delicate moldings, there’s a row of small Jenny Holzer screen prints on balsa wood, with phrases in red ink; one says MURDER HAS A SEXUAL SIDE. “I think art needs to provoke an emotion, or it’s not art,” Amon says. “Whether you hate it or you love it.”

While much of the furniture and artworks are by recognizable names, ranging from Charlotte Perriand to Jonas Wood, the choices are clearly those of a young collector who prioritizes the personal over the blue-chip. Amon has a thing for feminist artists, including Tracey Emin, but instead of one of Emin’s neon sculptures, which can often overwhelm a room, she has an inexpensive print of a neon piece in the front hallway. There’s a portrait by the young French painter Claire Tabouret of what appears to be a Victorian noblewoman wearing a leather dominatrix mask. The rope-shade lamp on a side table, which to an untrained eye might look like an impulse purchase from a Polynesian crafts store, is actually a ceramic Neptune’s-head sculpture by the Belgian artist Eric Croes. In the living room are a pair of requisite Serge Mouille chandeliers, but Amon couldn’t find the right lighting fixture for the dining room, so she asked a French plaster artisan to create a custom piece, inspired by the Alberto Giacometti chandeliers that sell for millions. “This one is not Giacometti, can you tell?” she says, laughing. Scattered around the tables and shelves are countless pots from Amon’s annual trips to Morocco, alongside 1950s German ceramics and other objects from her eBay and Etsy binges.

An antique palm tree lamp, in the dining room.

Photograph by Hugues Laurent; Styled by Gianluca Longo.

A vase from Anissa Kermiche, on a vintage cabinet.

Photograph by Hugues Laurent; Styled by Gianluca Longo.

Lately, due to her ever-expanding business, Amon has had less time to wander around flea markets or sip cocktails on yachts. “I used to party nonstop,” she says. “That’s over.” This year, she turned 30 and has taken up yoga and boxing. But by all accounts, her epic Paris wedding weekend was packed with a lifetime’s worth of social extravagance. It began on Friday with a takeover of Café de Flore for dinner and continued the next afternoon with a carnival garden party at the Musée Rodin. For the main event, at Versailles, that Sunday, every inch of the Orangerie was done up according to Amon’s self-described “control freak” specifications, down to the custom-made tableware and chair cushions. There was a finale of all-golden fireworks. Kanye West and Kim Kardashian had been famously turned down when they attempted to get married at Versailles, but Amon and Chichportich prevailed via what Amon calls some “very tricky” negotiations—helped by their donation for the restoration of the Orangerie’s 17th-century doors.

An Ettore Zaccari chair.

Photograph by Hugues Laurent; Styled by Gianluca Longo. Hair by Anais Lucas Sebagh at Open Space Paris; Makeup by Methta Gonthier at Open Talent Paris; Fashion Assistant: Clotilde Franceschi.

Amon tells me that she has only cried a few times as an adult. One was last February, when she heard that Lagerfeld had died. (She never met him in person.) Another was at her wedding, while she watched the intermingling among a wildly diverse set of guests who normally wouldn’t even occupy the same room, let alone celebrate together. The hodgepodge included art-school classmates, a few trans friends, a lot of wealthy Swiss, and that Twitter pal from Manila. “It was a weird mix of everyone,” she says. “Magical.”