There must be quite a few old mistresses approaching their dotage now in France who are going 'Tsk! Tsk!' at the conduct of Valerie Trierweiler, President Hollande's partner.
Madame Trierweiler has had a public spat with her lover's former partner, Segolene Royal.
There have been catfight text messages and tweets in the public realm and President Hollande's son, Thomas, has given a scorching interview about Valerie, deploring her demeanour.
It is reported that none of M Hollande's four children with Mademoiselle Royal wish to speak to Trierweiler, now dubbed 'the Rottweiler'. This is not the way mistresses and wives used to behave in the old French tradition.
In the past, conduct in these matters was set according to a correct pattern of honour, codified, established and recognised.
When I was 18, I was instructed in the ways of this decorum by a veteran Frenchwoman for whom I worked as a companion. "Now, little Marie," began the old dame, "what is the protocol when the wife meets the mistress at a social event?"
I had to admit that I was ignorant of the correct procedure.
"Well," she continued, "if they are of the same social standing, they kiss each other on both cheeks. However, if the mistress is just some little ballet dancer from the corps de ballet, the wife does not acknowledge. You understand?"
I understood. This wasn't about sex. This was about class. But the main point was that, at all costs, decorum must be maintained. Manners before morals.
French presidents had always followed these marital protocols. General De Gaulle was a faithful husband, so it didn't arise. But if one of his cabinet ministers were dallying with an extra-marital affair, the general would be tolerant, but insist on discretion.
It began to change with President Sarkozy, when his wife Carla's previous relationships were brought into the public realm.
The 'Tsk! Tsk!' of old mistresses began to be heard about preserving decorum. A man - or a woman - might have an amorous life outside the strictures of matrimony, but not in this bling-bling way. But then France was becoming more Americanised and modernised: divorce was growing and so were free unions. The old rules depended upon a certain measure of hypocrisy - those wives and mistresses kissing each other must have done so with gritted teeth.
But it's more difficult to have decorum where everything is much more in flux. Valerie Trierweiler is not Hollande's wife, but she is not a mistress, either.
Segolene Royal, the mother of his children, is not his wife but she has some claim to respect, which has hitherto not been forthcoming from La Rottweiler.
The latter has promised to "count to 10" before tweeting, or texting, anything inflammatory.
Perhaps that is the new version of protocols and decorum.