Through the ages, French kings have married for political reasons. They honoured their Queens just so... as protocol dictated they should. They honoured their mistresses like wives. Henri II married Cathérine de Médicis because he needed to build a political alliance with Rome, but he loved his mistress Diane de Poitiers his entire life. He was faithful to her. All the children from their union were legitimised. Diane de Poitiers' (the mistress') descendants count among the later Kings of France and Spain.
The French court and the French people honoured the mistress as the King's one true love, and the Queen as a political contract in the same way organisations honour business contracts. The King stayed loyal to his true love (his mistress, not his Queen) and gave her (his mistress, not his Queen) every respect due to the Mother of his children, and his chosen partner in life.
Thus, it comes as no surprise that Mme Valerie Trierweiler, whilst not married to the French President François Hollande, had an Élysée office and staff to help her in her official role as the French First Lady. She was his chosen partner and she had work to do by his side. She could not do it alone, because it really was a lot of work.
The French people object not at all to their leaders' mistresses. The institution of marriage and the conduct of true love are quite separate in the minds of the French. The public persona of the King required a Queen. The private persona of the King required a woman to love, and who loved him back. With such a historical background, the French people are tolerant of mistresses. François Mittérand had a wife and a mistress too. He looked after both his families well, and the French approved of this Real Man.
The shocking thing about François Hollande is that he seems to have behaved very irresponsibly. He broke up with Ségolène Royal, the mother of his 4 children... and escaped without a divorce settlement because he wasn't married to her in the first place. In the absence of CONTRACTUAL loyalty, French leaders had always proven themselves EMOTIONALLY loyal to their women. Not so François Hollande who cheated on Ségolène Royal for years... and was recently caught out, cheating on his 2nd "maîtresse en titre", Mme Valerie Trierweiler.
So ummm... who is François Hollande's true love?
The French people are outraged, not because their President has a mistress, but because he should have conducted himself in so disloyal a manner towards Her whom everyone had believed to be his true love.
Mme Trierweiler was unceremoniously dumped with not so much as a By Your Leave. Again, it was done without a divorce settlement. Contrast this with how Rupert Murdoch treated his 3rd wife. He left her a USD 44 million apartment so that his 2 children with her would still get to stay in New York, and go to the same school as they have always been attending. He no longer loved his 3rd wife but he discharged his responsibility as an ex-husband.
One notes also that both Ségolène Royal (an ex-Presidential candidate) and Valérie Trierweiler (a senior Paris Match journalist) were powerful women in their own right. Over the years, François Hollande's relationships with both women would have paid political dividends for him. In short, that François Hollande is today the President of France would have been due in large part to the support of both women.
Then he dumped them? One of them gave him 4 children?
I've always found admirable how a French man doesn't need a wedding ring nor a wedding certificate to stand by his woman. The bonds of love are enough. François Hollande, it appears, breaks the mould. Here is a French man with whom one should have signed a pre-nuptial and made very sure of a marriage certificate in order to compel him to do his duty towards the mother of his children... and his ex-First Lady.