During the era of absolutism, what would a minor mistress of the french king be called in polite, but maybe slightly salacious society? I don't mean the official royal mistress, but someone he might have "at the side" apart from that. I think I've heard "madame du jour" (lady of the day) in this context, but I'm not sure. Is that a common euphemism for "mistress"?
(For those who need more details: I need a way to describe the young lovers Luis XV had while Madame de Pompadour was still his official mistress by title, and his friend, but no longer shared his bed due to her declining health.)
Also, would an absolutist king parade his mistress around in court (have her hanging onto his arm or something like that), or would that be seen as too much of an affront to the queen?