Peel away the facade of fabulousness and the life of even the most powerful style star is often far more fragile than it seems.

Take John Demsey, the former Executive Group President at the Estée Lauder Companies. A three-decade Lauder stalwart, Demsey helped steer the company from a mid-sized privately-run family concern to a publicly-traded cosmetics giant worth, at its peak, over $100 billion.

Last winter, as his father lay gravely ill and his mother began battling cancer, the rest of Demsey’s world unexpectedly imploded. In early March 2022, Demsey was forced to retire from Lauder after he reposted an Instagram meme that contained the N-word.

Demsey insisted he’d misinterpreted the meme, which was initially shared by the rapper Chingy.

Despite removing the post within hours, pressure from both Lauder employees and “call-out” accounts like Estee Laundry saw Demsey’s 31-year career at Lauder end in barely a week. Branded a racist — and quieted as part of a legal agreement with his former employer — Demsey had been canceled.

“It felt like I’d been the victim of an identity theft,” Demsey, 67, told The Post in an exclusive interview, his first since the Instagram fiasco 18 months earlier. “I made a mistake and I corrected it. But the life I had before this happened simply does not exist anymore.”

The mementos of that life cover nearly every surface of the six-story East Side townhouse, which Demsey, who’s divorced, bought in 2018 and shares with his 14-year-old daughter, Marie-Hélène, eight dogs, and a pair of cats.

Demsey has spent the majority of his post-Lauder existence here — sometimes angry, sometimes depressed, often exercising (he’s dropped 35 pounds), but mostly cooped-up and clearly contrite.

“I almost feel like I’ve been under house arrest,” he deadpanned. “And when I do go out, people act as if they’ve sat shiva for me.”

In the multi-billion dollar world of luxury and beauty, few stars cast a wider shine than Demsey. Tall and imposing, the Stanford-educated exec was equally adept at creating buzz and making money.

“Demsey has always had a deep sense of what consumers want before they want it,” said Professor Thomai Serdari, Director of the Fashion and Luxury MBA Program at New York University, of Demsey’s tenure at Lauder. “He is very good at commercializing brands … while providing the glue that makes ventures work.”

Demsey’s presence at Lauder was particularly potent in two areas: far-sighted advertising campaigns and his chairmanship of the MAC AIDS fund, which has raised $500 million for HIV research over the past 25 years.

In the ad world, Demsey is best known for the decades of VivaGlam promotions he oversaw for MAC Many of their stars were black — RuPaul, Rihanna, Diana Ross, Missy Elliott, Nicki Minaj. And Demsey’s intimacy with African-American artistry provided him with a level of racial maneuverability rarely afforded to white execs.

Demsey’s presence at Lauder was particularly potent in two areas: far-sighted advertising campaigns and his chairmanship of the MAC AIDS fund, which has raised $500 million for HIV research over the past 25 years.

“Long before the era of George Floyd, John was one of the most culturally attuned people when it came to inclusivity,” longtime former Wall Street Journal fashion reporter Teri Agins told The Post. “John was accepted by black people because it always felt like he was in the culture.”

Dressed in a tan suit and Zegna sneakers, Demsey displayed both incredulousness and humility as he recounted the events of the past year. He freely described his actions on social media as “stupid and impulsive” — a casualty of the near-manic Instagramming which overtook him during Covid.

“I was posting like 20 or 30 times a day,” he said. “People really responded to it and it just became this sort of a thing.”

The Chingy meme, Demsey explained, appeared randomly in his feed — a Covid-era Big Bird tending to a bed-ridden Snuffleupagus accompanied by the phrase “My n***a Snuffy done got the ’rona at a Chingy concert.”

Demsey insists he read n***a as “nanna” — a nod to Snuffleupagus’ grandmotherly get-up.

“I’ve never used that word in my life,” Demsey said of the racial slur he’s accused of promoting.

Even though Chingy himself went on Instagram to defend him, no one else will ever really know what Demsey was thinking when he pushed that share button.