In the salons of the Quai d'Orsay, the protocol boffins at the French foreign ministry are straining over an interesting conundrum: what to call the new First Lady?
The problem is that for the first time ever in France, the incoming presidential couple are not man and wife.
Francois Hollande and the journalist Valerie Trierweiler have been together since 2005; openly so since 2007, when Mr Hollande's relationship with fellow Socialist Segolene Royal was publicly ended.
Theirs is by all accounts a devoted partnership. Ms Trierweiler was at Mr Hollande's side throughout the campaign, with an office at his HQ.
She gives him regular advice, and is credited with having masterminded his "relooking" - the makeover and weight-loss programme that preceded his presidential candidacy.'Impoverished bourgeoisie'
Many will have a got a first look at Ms Trierweiler during the victory celebrations at the Bastille on Sunday night: an attractive woman of 47 with thick chestnut hair, clearly delighted by her partner's triumph.
After the exotic glamour of Carla Bruni - and before her the buttoned-up correctness of Bernadette Chirac - she will offer a very different version of the presidential consort.
Ms Trierweiler's origins are not exactly humble, but certainly rather more ordinary than the backgrounds of her predecessors. In her own words, she comes from a family of "impoverished bourgeoisie".
Her paternal grandfather owned a bank in the western town of Angers, but by the time Valerie Massonneau was born in 1965 the affluence had long since petered out.
Her father lost his leg at the age of 12 while playing with an unexploded shell in World War II. They lived in a council house in Angers, and her mother did part-time work as a cashier at a local skating-rink.
One of six brothers and sisters, Valerie had ambition and came to Paris to study politics. She started in journalism at the now-defunct magazine Profession Politique, and in 1989 was taken on as a political reporter at Paris Match, where she has been ever since.
Funnily enough one of her early assignments was to interview the 38-year-old Segolene Royal, who in 1992 had just given birth to her fourth child with Francois Hollande.
Ms Royal was environment minister at the time - she was the first ever French minister to give birth in office - and spoke to Ms Trierweiler in her hospital room.'Part of the film'
Ms Trierweiler briefly met Mr Hollande a few years earlier, but their friendship deepened from 2000 when they met often in the corridors of the National Assembly.
"We both loved politics, and we both loved to have a laugh," she told one interviewer.
Today Trierweiler says she has to pinch herself to believe the extraordinary change that suddenly come upon her life.
"It's a bit like I am the subject of one of my own despatches," she said. "You know that film in which a person in the audience enters the screen and becomes part of the film. It's like that."
Pestered by questions about how she will approach her new life, Ms Trierweiler has said she needs time to work it out.
The couple have indicated they do not intend to live in the Elysee palace, but they have been told by the presidential security people that their current residence in the 15th arrondissement of Paris is unsuitable.
As much as possible, she wants to maintain her previous lifestyle. She has three children by her former husband Denis Trierweiler, two of whom are taking the baccalaureate in June.
She also intends to keep on with her journalism - though she has already been obliged to give up writing on politics because of her relationship with Mr Hollande.'Sexism'
"It is going to be very complicated," said the journalist and writer Philippe Labro, who gave her a job as political interviewer on the TV station Direct8.
"She is someone who has always worked, who's come from nowhere, who's done everything for herself. I understand her point of view, but it's going to be very hard to keep doing that and be First Lady."
One thing she should understand well, given her background at Paris Match, are the demands of the celebrity press - though a recent contretemps with her own employer suggests there could still be tensions to come.
When the magazine published a large and favourable photo-story about her on 8 March (International Women's Rights Day), she tweeted: "Bravo to the sexism of Paris-Match."
As for the protocol, no-one seriously thinks the marital status of Mr Hollande and Ms Trierweiler presents a problem.
Times have changed - and today being unmarried is as "normal" (Hollande's watchword) as being married.
There just remains the tricky question of what to call her. Conjoint? Compagne? Maybe. Or conceivably Madame Hollande?
The couple have said they will not get married purely for reasons of protocol.
But for reasons of love? They haven't ruled it out.