The shocking news about the French president’s ill-fated tryst with his mistress spread quickly. While taking a break from the urgent political matters of the day, the head of state literally succumbed to his passion in a salon at the Elysee Palace, suffering a cerebral hemorrhage, and dying in the arms of his lover, who fled half-naked after raising the alarm.

We’re not talking about Francois Hollande, the current occupant of the Elysee who is dealing with a very public domestic crisis of his own, but a predecessor, President Felix Faure, whose death at age 58 on Feb. 16, 1899, at the height of the infamous “Affaire Dreyfus,” sparked intense speculation.

“He sacrificed too much to Venus” is how one newspaper decorously described it the next day. Other papers were less coy, making suggestions about the aphrodisiac the president had supposedly ingested and the sex act that had proved fatal. Some relayed rumors about poison, saw connections to Dreyfus or simply remarked on the character of his lover, Marguerite Steinheil, the wife of a painter.

There is nothing new about French presidents having lovers, nor about the media storm that ensues when their liaisons are exposed. What has changed in France, however, are basic notions about family values and what constitutes the norm in personal relationships.

French leaders dating back to the royal courts of Louis XIV and earlier have had mistresses, but they also had wives. That’s no longer the case. Even though two-thirds of French people describe themselves as Catholic, the institution of marriage is in full retreat. Moreover, the standard model of the nuclear family consisting of two married adults with children has, in the past decade, been superseded by many other, less traditional arrangements.

Hollande is living proof of this shift in attitudes: He took office as the first president not to be married to his partner, who moved into the Elysee with him. He has four children from a previous partner, Segolene Royal, to whom he wasn’t married, either. His current partner, Valerie Trierweiler, has three children from her second marriage. Hollande’s predecessor, Nicolas Sarkozy, has two sons from his first wife, another son from the second, whom he divorced shortly after taking office in 2007. He also has a young daughter with his current wife, Carla Bruni, whom he married in 2008.

Unlike in the U.S., such nontraditional arrangements enjoy wide acceptance in France. In a poll taken before the latest revelations about Hollande, 91 percent of French voters said they simply don’t care about the family lives or sexual preferences of their politicians.

The turning point in this social and cultural transformation occurred in 1999, with a law that created a new civil union known as the PACS, an acronym for “civil solidarity pact.” It establishes a set or rights and duties for couples governing such matters as ownership of property, taxation and inheritance.

Before the law was changed last year to allow homosexual marriage, some gay couples used these civil unions to gain formal status. However, heterosexuals have made by far the most use of them; just 5 percent of the civil unions in France involve gay couples. A similar pattern is apparent in other European countries. Nineteen of the 28 European Union nations have some sort of civil-union legislation, and the number of marriages per 1,000 people has dropped sharply -- by 36 percent since 1970. In France it has dropped by more than half, to 3.7 per 1,000 in 2011 from 7.8 per 1,000 in 1970.

Moreover, almost 40 percent of children are now born to unmarried parents, compared with less than 1 in 5 in 1990, according to EU statistics. In 2010, the majority -- 55 percent -- of French children were born outside of marriage.

The number of heterosexual marriages in France also dropped sharply in the first five years after passage of the civil-union law. It then stabilized, but it has since resumed its decline: The number of marriages was about 20 percent lower in 2013 than a decade earlier. There are now two PACS unions for every three marriages, according to a 2013 study by Insee, the French national statistics office.

The other striking sign of change in the makeup of French households is the growth in the number of what are officially known as “familles recomposees” -- blended families, involving couples who bring children from previous relationships and then have more children together. About 9 percent of all French families with children under the age of 18 are now blended, according to a 2011 study, and such arrangements now involve more than 10 percent of the 14 million children under 18 in France. A further 2.5 million children live in one-parent families; the remaining 10 million are in traditional families.

For all the public tolerance of these arrangements, the Catholic Church in France is frustrated and bemused at what it sees as deliberate government efforts to undermine marriage. Last November, the senior French Catholic bishop, Monsignor Georges Pontier, issued a thinly veiled critique of the government. Referring to the century-old separation of church and state in France, he said that “it’s the state that needs to observe a benevolent neutrality.”

He spoke after the church stepped heavily into the political arena earlier in the year, openly backing a movement that opposed plans to legalize gay marriage. The campaign failed, the gay-marriage law passed, but the mass demonstrations in the first few months of the year haven’t ended. A gathering against “family-phobia” is scheduled to take place Feb. 2.

The affaire Hollande may or may not have a lasting effect on France’s politics or affected the president’s already dismal standing with the public. It has, however, exposed anew a contradiction in French society: For all the professed indifference to politicians’ conduct of their private lives the French express in polls, they demonstrate as much prurient interest as any other nationality when peccadilloes are brought to light. Welcome to political correctness, French-style.

(Peter Gumbel, a Paris-based journalist, is the author, most recently, of “France’s Got Talent: The Woeful Consequences of French Elitism.”)

To contact the writer of this article: Peter Gumbel at Petergumbel@orange.fr.

To contact the editor responsible for this article: Max Berley at mberley@bloomberg.net.