Julie Gayet, the French actress, is pressing charges for "violation of privacy" against the magazine that published photos it said proves she is Francois Hollande's mistress, according to French reports.
Mr Hollande has expressed his "total outrage" at the publication in 'Closer' magazine of seven pages of photos showing Ms Gayet arriving at a flat, a stone's throw from the Elysee, followed by a helmet-clad man on a scooter it said was the president.
At a press conference yesterday, he admitted that he was enduring "painful" times with Valerie Trierweiler, his current partner and de facto First Lady.
But the Socialist president, who has not denied the affair, said he would not be pressing charges for violation of privacy as it would be seen as "double standards" given that he enjoys presidential immunity.
However, according to RTL radio, the 41-year old actress to whom he has reportedly been paying regular nocturnal visits has decided to take legal action. Despite the furore over the affair, Ms Gayet's ex-husband yesterday said she had remained "very calm".
"It's obviously not easy. At the same time, she's very calm about it all and very sure of herself, I think, because there was no fault, no betrayal," said Santiago Amigorena, an Argentinian writer and father of their two children.
Mr Hollande was also reportedly relaxed and jovial after yesterday's press conference. After he dropped in on a group of French journalists still at the Elysee for a debrief, 'Le Monde' said: "He was more amiable than we have seen him for a long time."
"It was as if political as well as personal adversity were the best kind of fuel for calm".
Mr Hollande promised to provide "clarification" before a visit to the White House next month when France's first couple are due to stay with Barack and Michelle Obama. And while Mr Hollande's cabinet ministers were tight-lipped about his alleged amorous escapades, privately some were said to be appalled at his antics.
"He's behaving like a teenager," Manuel Valls, his interior minister, is reported to have exclaimed by 'Le Canard Enchaine', the satirical and investigative weekly.
Others were reportedly worried about the security risks he had taken. "If a photographer was able to take snaps, a killer could have assassinated him," one is cited as saying in 'Le Canard'.
In his defence, Mr Hollande told 'Le Monde' he was no more exposed than when Nicolas Sarkozy, his conservative predecessor, went "jogging round the Elysee". Mr Sarkozy, who his Socialist rival has often accused of shamelessly exploiting his private life for political gain, has reportedly been gloating over his woes.
"Perhaps this will put an end to all his moralising," 'Le Canard' quotes him as telling "visitors". "If everyone has the right to a private life, when one is a public figure and president, one must be careful to avoid the ridiculous.
"Well, that photo of Hollande coming out of his mistress' place with a motorbike helmet makes Hollande look totally ridiculous," he said.