France's most revered actress was among 100 prominent women to sign a letter in Le Monde this week defending a man's right to "bother" women, complaining that the campaign against harassment had become "puritanical".
For hordes of young feminists taking to the internet, 74-year-old Deneuve's defence of men who flirt insistently -- even when such attentions are unwanted -- are the words of a generation that has had its time.
"Their world is disappearing," some 30 activists wrote in a riposte, comparing the letter to "a tired old uncle who doesn't understand what is happening".
Deneuve and dozens of other performers, writers and academics argued that women should not have to feel guilty about being an object of sexual pleasure.
Women complaining of being traumatised after a man rubs up against them on the metro, they added, should just get over it.
And the idea of someone being forced to resign "just" for touching a woman's knee or trying to plant a kiss is for them outrageous.
For some readers abroad, these comments fit comfortably with cliches of France as a nation that revels in the art of seduction.
But New Yorker correspondent Lauren Collins was among those urging foreigners to resist attributing the letter "to some innately French point of view".
She noted that France's answer to the "Me Too" hashtag, "BalanceTonPorc" or "Squeal on your pig", had led to a similarly prolific outpouring of tales of harassment -- though far fewer high-profile figures have been named and shamed.
France, where surveys suggest at least half of all women have suffered some form of harassment, is no stranger to public debates over how to tackle everything from persistent catcalling to rampant domestic abuse.
The government announced new legislation against harassment in October, with President Emmanuel Macron denouncing a society that was "riddled with sexism" in November as the Me Too campaign gained pace.
In 2011 rape accusations against former IMF chief Dominic Strauss-Kahn revealed that the Frenchman had long had a reputation as a sexual predator -- raising questions over how such behaviour went quietly tolerated for so long.
Sociologists say that if there is anything specifically French about the Deneuve row, it is the letter's defence of apparently "gallant" men who, its signatories argue, should be freely allowed to pursue the opposite sex.
"We're a bit 'poisoned' in France, in inverted commas, by this idea of gallantry as an expression of French culture and civilisation," cultural historian Michelle Perrot told AFP.
For supporters, this idea of the red-blooded Frenchman who seeks to charm every woman around him is held up as positive, she said.
"It's an interesting and brilliant myth, but it covers at its heart a specific kind of domination of men over women in our country."
Francoise Picq, a historian of feminism, said this culture of "gallantry a la francaise" had roots that go back centuries.
"Since the Middle Ages, we've called this 'courtly love' -- a poetic tradition of writing verse about women, of putting them on a pedestal," she said.
She blasted this tradition as "perverse", discouraging women from rising up and encouraging them to see themselves instead as prized possessions.
On the contrary, Deneuve and her co-signers argue that it is the Me Too movement that encourages women to see themselves as victims.
The actress has found support in many corners, including from some men.
"What I like is that women are speaking out to say what men have not been able to say for months -- that we are not all pigs," the writer Frederic Beigbeder told France Inter radio.
But the letter has exposed something of a generational divide, with many younger feminists saying she does not speak for them.
The open letter written in riposte to Deneuve, and published by France Info online, has gone similarly viral.
Author of 'The Sexual Life of Catherine M', Catherine Millet. Photo: AFP
Led by the leftwing activist Caroline De Haas -- who at 37 is exactly half Deneuve's age -- its signatories are notably younger and less white than the signatories of the original statement.
Deneuve and the other writers, academics and performers who signed anti-Me Too the letter with her have been successful in life, and critics say their cultural assumptions came across.
Web users have lashed out at the downplaying of rampant sexual assaults on the metro, a form of transport that the star presumably does not use.
"You have a bodyguard, you're rich, you have a chauffeur," tweeted 24-year-old user @Cloe_Rennes_35.
"Ride the metro all on your own at midnight, and we'll talk again."