The phrase 'Je ne sais quoi', certainly applies to French President Francois Hollande. Women around the world are looking at each other in wonderment. What are we missing? He seems so ... grey.
What does Hollande have that makes beautiful women want to hop into bed with him. What do they see that we don't?
It seems that beneath their bland exterior, leaders who look grey and uninteresting are often quite the opposite in their private lives.
Who can forget the revelation that John Major was sleeping with Edwina Currie. No one saw that coming, least of all his poor wife. Nor did anyone think Monsieur Hollande was going to turn into the lothario of the Elysee Palace.
For a man who looks like he'd put you in a coma if you sat beside him at a dinner party, he certainly seems to have a large dose of 'je ne sais quoi'.
Apparently Hollande has been carrying on a secret affair with Julie Gavet, a beautiful French actress, 18 years his junior, for quite some time.
One can only assume that the French president is a busy man in his public life and he certainly has a full schedule in his private life. Hollande spent New Year's Eve with his partner, France's first lady, Valerie Trierweiler, at the Lanterne, a presidential retreat next to the Versaille Palace, and St Stephen's Day with Trierweiler's family. But he allegedly spent the nights either side of New Year with Julie Gayet.
His preferred mode of transport to and from his illicit rendezvous is on a moped with his bodyguard. Well, with a packed timetable like that, you can't afford to get stuck in pesky traffic.
When the story of the affair broke, Trierweiler collapsed and was rushed to hospital for exhaustion and depression. Some of Hollande's Elysee advisers are reportedly furious at the leak about Trierweiler's hospitalisation. They suspect she is using the incident, and surrounding drama, as a form of emotional blackmail.
Trierweiler is, after all, a journalist who writes for celebrity magazine 'Paris Match', so she's bound to have a few tricks up her sleeve. As first lady, she has enjoyed all the perks of a presidential wife with a retinue of staff and a generous budget. She has five staff working for her at a cost of €20,000 a month. Her taxpayer-funded perks also include homes across France with private jets and limousines at her disposal.
It's not easy to give all that up and it has been reported that after a few days of rest and reflection, Trierweiler is now ready to forgive Hollande but only if she receives clarification about his intentions.
Unfortunately for the first lady she is deeply unpopular in France. An online poll showed that 89 per cent of the French think the president should announce his separation from Trierweiler. This would result in her becoming the first premiere femme in history to be kicked out of the Elysee Palace.
Trierweiler became Hollande's live-in girlfriend following his separation from fellow Socialist politician Segolene Royal, the mother of his four children. Hollande is said to have taken her as his mistress while still living with Ms Royal. Trierweiler clearly didn't think of the old adage 'when the mistress becomes the lady of the house, a vacancy opens up'...
France has some of the strictest privacy laws in the world and previous French presidents Nicolas Sarkozy, Jacques Chirac and Francois Mitterrand all secretly cheated on their wives. Our own Charles J Haughey was a man who admired all things French and not just the Charvet shirts. He appreciated the open French attitude to mistresses and often travelled to France with his own mistress, Terry Keane.
But this time, no one is turning a blind eye. Hollande's ménage a trois is so juicy it has all of France talking.
The country is buzzing with speculation over who tipped off the magazine -- some are suggesting it was the president himself as a way of getting rid of Trierweiler. And to add that little extra drama, it has been reported that the apartment Hollande used during his affair with Gayet has been linked to Corsican Mafia figures.
Who needs soap operas? Hollande is more entertaining than any script. The world waits with bated breath for the next instalment in this fascinating French farce.