Warning: mild spoilers for The Idea of You below.

In The Idea of You, the smoking hot connection between Solène (Anne Hathaway), a 40-year-old Silver Lake art gallery owner, and boy band heartthrob Hayes Campbell (Nicholas Galitzine) may be the focus of many a fan-fic dream. But, the supporting fashion in the Michael Showalter-directed rom-com will also make for impassioned talking points and sartorial yearning. After a Coachella meet-cute, a whirlwind romance ensues—featuring sublime vintage Chanel, Gucci and Versace on Solène, snuggly streetwear cardigans on 24-year-old Hayes and a high-style sequence that’s fantastical in its own right.

Ahead, costume designer Jacqueline Demeterio, whose fashion bonafides count the New York City publishing world-set Younger, (and working on Patricia Field’s team on the Sex and the City movies), takes us through the couple’s swoony story, and wardrobe, arcs. Plus, she responds to the elephant in the room: How does Harry Styles factor into it all?

Solène’s “French Girl” by Way of Silver Lake Style

The newly single Solène, who’s co-parenting teen daughter Izzy (Ella Rubin), remains confident and content into her next stage—as reflected in her arty-chic SoCal style. “Anne and I both worked on curating this effortless, cool wardrobe for Solène,” says Demeterio, who previously worked with Hathaway on 2022’s WeCrashed.

Solène’s assured attitude is illustrated by her high-waisted and perfectly worn-in vintage Levi’s, discovered by Kismet—akin to her fateful first encounter with Hayes after venturing into the wrong trailer at ‘Chella. “[The jeans are from] our second fitting, and that’s where we found Solène’s character: the Jane Birkin feeling. Just a cool French girl,” says Demeterio, also speaking to Solène’s heritage. In the production notes, Hathaway refers to the denim as “magical,” adding, “Suddenly, it was like Solène had arrived. Any shoe, any top, any jacket looked good with those jeans.”

For her 40th birthday party, Solène dons a black, cropped Tom Ford jacket with flowing fringe on the sleeves, which Demeterio imagines to be another notable wardrobe staple. “It just had such great movement,” says the costume designer, who borrowed the vintage gem from the Albright Fashion Library. “It’s that piece that Solène just throws on to elevate [a look] and gives you a hint of this rock star thing about to come.”

Solène’s Fiery Color Palette

Demeterio and Hathaway also determined a soulfully expressive, jewel-toned purple and blue signature for Solène. “It just felt right. It felt vibrant,” says Demeterio.

When Hayes makes a surprise appearance at her gallery, Solène is dressed for her creative, client-facing job in her trademark hues and tactile fabrics: an indigo velvet Etro blazer over a vintage strapless Chanel dress, with a chenille bodice and purple scarf-print skirting. Solène’s jacket signals her work uniform. But, the plush layer—or shedding of—also serves as a signifier, especially as the temperatures heat up, literally and figuratively, throughout the duo’s day together.

“They were getting more comfortable with each other, and, yes, she’s warm and she felt comfortable enough to take her jacket off,” says Demeterio. “The dress is so sexy without the blazer. There was this seductive feel about the chenille, the color and the brilliance of it, with bare arms and shoulders. It all worked.”

Hayes’s Boy Band Fashion Influences

To make Hayes his own character, Demeterio looked to a range of musical genres for inspiration, from NSYNC for a “casual feel” to the Jonas Brothers for a “designer-y” touch, to The Chainsmokers for a “casual, but cool” vibe. In response to yet another inquiry about how much the “As It Was” singer and fashion icon influenced Hayes’ designer cardigans, tank tops and blousy, wide-leg trousers, Demeterio responds, “Everybody’s been asking. I had images of Harry Styles on the mood board in some things. But more of his street looks, not his stage stuff.”

After experimenting with various looks, from “dressy and a little shiny” to “glam rock” for Hayes, she and Galitzine landed on an aesthetic of Saint Laurent and Margiela hoodies, sporty streetwear jackets from Adish and Karu and Jungmaven sleeveless t-shirts, which Demeterio’s team custom-tailored to fit (and reveal a smattering of tattoos). “This checks all the boxes. He looks really attractive. He looks cool. He looks confident,” says Demeterio.

When Hayes flexes and buys out Solène’s entire gallery, he still exudes warmth and guileless sincerity in a nubby Isabel Marant ombré cardigan over a Bottega Veneta tank, with a low-sweep neckline and slouchy Loewe trousers. “Those are really cool silhouettes that his stylists would bring in on racks for a fitting,” says Demeterio. “Hayes definitely knows what’s happening with fashion.”

Solène’s Sultry Weekend Outfit

With Izzy conveniently spending summer at sleepaway camp, Solène spontaneously flies cross-country to meet Hayes in New York City. She strolls into his luxury suite in a Dior trench over a white, gauzy bodycon top and skirt by Fendi and strappy, sky-high Alaia stilettos — instead of her usual sneakers. “New dress?” asks Hayes, teasingly, before it ultimately comes off.

“She had that moment of, ‘I’m gonna go for it. I’m not treading lightly. I’m fully just gonna do it. I’m wearing the sexy sheer [outfit],’” says Demeterio. “So she arrives knowing how sexy and amazing she looks and knows what she’s going there for: a hot weekend. It was a definite choice to go in that direction.”

Solène’s European Fashion Adventures

Hayes then invites Solène to join him on the European leg of his band August Moon’s tour, but she only packed a carry-on. So, he offers the services of his “army of stylists.”

A montage of romantic moments and high fashion ensues, featuring quick flashes of late-night walks in a Galvan halter top and mermaid skirt (and a white cami by The Row with a Rick Owens green silk skirt and Chanel gold sandals), plus backstage access in vintage Versace leather pants, a Tom Ford gold knit tank and a Balmain black velvet jacket. Solène also trades in her practical brown leather Isabel Marant tote for a bold little Paco Rabanne bag, which returns to L.A. with her.

Unknowingly snapped by the paps, Solène frolics with Hayes on an idyllic beach, stunning in a blue string bikini. The bold Eres look speaks to Solène’s trademark colors—and not to Olivia Wilde’s similarly-hued two-piece for a 2021 Italian jaunt with Styles. (Demeterio emphasizes that Robinne Lee’s 2017 bestseller, on which the film is based, came out years before the duo, with a ten-year age gap, dated.)

At one point, Solène peruses a rack of even more stylist offerings, while already outfitted in a vintage Gucci olive silk jacket and crushed velvet trousers, a tank and heels by Saint Laurent. “She goes through all the racks of clothes, all the accessories, this and that. But it was important for Anne and I that it would still feel like [the European wardrobe evolution) was in Solène’s wheelhouse,” says Demeterio, about Solène staying true to herself and her established—and proven—taste during her thrilling new adventures with Hayes. “It was definitely more sexy though, like she was feeling this confidence with him—and feeling all the feels.”

Toward the end of the movie, Solène ponders the greater consequences of their relationship. She stands strong, but reveals vulnerability in a delicately pleated lilac halter dress, with dainty bows at the shoulders, by Acne. ‘The artwork behind her was the same color of the dress,” says Demeterio, about the full frame of purples evoking Solène’s overwhelming emotions. “I was like wait a second, because that was her color.”

The Idea of You is now streaming on Prime Video.