The devil wore Calvins?

“Love Story” — the Ryan Murphy series about Carolyn Bessette and John F. Kennedy Jr.’s whirlwind New York City romance — is #1 on Hulu, and enamored fans are taking to social media to post photos of themselves in her signature looks and going to the campy Panna II Indian restaurant in the East Village.

Alas, don’t believe everything you see.

The show’s depiction of Bessette’s workplace at the Manhattan office of fashion designer Calvin Klein is hardly like real life, according to one woman who was also there in the ’90s.

Those red roses that JFK Jr. (played by Paul Kelly) sends Bessette (Sarah Pidgeon) at work on the show?

“Love Story” — the Ryan Murphy series about Carolyn Bessette and John F. Kennedy Jr.’s whirlwind New York City romance — is #1 on Hulu, and enamored fans are posting photos of themselves in her signature looks. FX

Calvin would never.

Instead, flowers had to be white — preferably Calla lilies —  according to Kara Mendelsohn who, like the late Bessette, started as a sales associate at Calvin Klein when she was in her early twenties.

“You weren’t allowed to have personal photos [on your desk],” Mendelsohn, 50, told The Post. “We had strict rules — you weren’t allowed to talk to [Klein], look at him. It really was, unless he asked you a question, you were not to speak to him.”

Mendelsohn took to TikTok Monday to recount her experience working at Calvin Klein. “Eating in general was off limits. I was chugging a can of Slim Fast,” Mendelsohn told The Post. @kmendelsohn/TikTok Bessette (Sarah Pidgeon) receives red roses from JFK Jr. at her office on the show. But red roses were forbidden in the Calvin Klein showroom, Mendelsohn said — along with nail polish and, “generally,” food. FX

The Long Island resident, who now does consulting and content creation for a living, has been watching the show and sharing her memories — and corrections — with her 84,000 Instagram and 39,000 TikTok followers.

Working for Klein in the ’90s — when the brand was famous for its clean style and controversial underwear ads with Kate Moss and Mark Wahlberg — was a Manhattan dream job. It also required minimal makeup, polish-free nails and absolutely no eating in the presence of the designer, now 83 and retired from his namesake brand.

In “Love Story,” viewers see an associate hastily clearing a Tupperware of salad off her desk when Klein (played by Alessandro Nivola) enters the showroom.

“Eating in general was off limits,” Mendelsohn told The Post. “I was chugging a can of Slim Fast.”

Bessette fans are recreating her iconic minimalist looks from the ’90s on TikTok. @zibalennox/TikTok Fans are also visiting the East Village Indian restaurant Panna II, shown on “Love Story” during a Carolyn Bessette and JFK Jr. date night. Stephen Yang for NY Post

Her other sustenance? Parliament Lights, sneaked out the window. That is, when she could escape her “office.”

“They had two of us in a closet where the models got changed. Half the time there was a naked girl behind us while we were working because that was the only space,” Mendelsohn recalled of the space that had no windows or ventilation and was constantly “freezing.” 

One thing she says the show gets right: Bessette painstakingly measuring the space between shoes displayed in the showroom, recalling Klein used to do the same thing. 

“Everything had to be perfect. At night, when I had to leave, I had to clear my entire desk,” she recalled.

Like Bessette, Kara Mendelsohn worked at Calvin Klein as a sales associate in the late ’90s — and is sharing her memories, and corrections of “Love Story,” with her 84,000 Instagram and 39,000 TikTok followers. Courtesy of Mendelsohn “Everything had to be perfect. At night, when I had to leave, I had to clear my entire desk,” Mendelsohn recalled of working at Calvin Klein, as portrayed on “Love Story” (above). FX

While Bessette encounters Kate Moss and Annette Bening on the series, Mendelsohn also kept her mouth shut around celebs — like when she wrangled Gwyneth Paltrow at a fashion show.

“We had to hustle the VIPs into the elevator quickly and to their seats. Gwyneth just won the Oscar for ‘Shakespeare In Love.’ They had her flown into the show. We weren’t allowed to look or talk to her!” Mendelsohn said.

Pidgeon recently told The Hollywood Reporter how her hair and wardrobe were adjusted after early backlash against photos of her filming on the streets of New York City. Mendelsohn said Bessette’s iconic look — including what Bessette’s colorist Brad Johns calls “child-of-the-beach” blonde hair — was how every girl wanted to look.

“Everyone’s makeup looked like Carolyn’s. We had very thin eyebrows – it was the ’90s,” Mendelsohn said on TikTok.

Mendelsohn (left) with her former Calvin Klein colleagues in the late 90s. “Everyone’s makeup looked like Carolyn’s. We had very thin eyebrows – it was the ’90s,” Mendelsohn said on TikTok. Courtesy of Mendelsohn JFK Jr. and Carolyn Bessette Kennedy met via Calvin Klein in 1992, according to Elizabeth Beller’s book, “Once Upon a Time: The Captivating Life of Carolyn Bessette-Kennedy,” which inspired the Hulu show, “Love Story.” Getty Images

Mendelsohn never worked alongside Bessette, who rose through the Klein ranks to dress VIP clients, then became the director of publicity and, finally, produced runway shows. Bessette quit before marrying Kennedy — whom she met on the job — in 1996, three years before they died in a plane crash.

While not everything on the show is accurate, Mendelsohn said she’s enjoying it and gets why young women are romanticizing her past.

“It was the place to be,” Mendelsohn, who stayed at Calvin Klein for two years, recalled of the job. “I worked very late nights making $25,000 — the expectation was, if you don’t want this there’s 100 girls who do. You came, you worked hard, you kept your mouth shut.”

A major moment in Mendelsohn’s early career working at Calvin Klein was when she was asked to escort Gwyneth Paltrow to her seat — and not say a single word to her — during a fashion show. Courtesy of Mendelsohn

One priceless memory? No phones and no social media.

“If you had an event after work, you would go from the office. Everyone was doing drugs and smoking,” she said. “You could smoke in a restaurant. That was something you did with your hands instead of looking at your phone.”