All,
I agree with Michael and Brandon. Guggenheim was a man of his class and time. He must be seen within that context and not through our modern eyes.
Really, though, things haven't changed so much. If we are to believe what the sex therapists say, most married men have affairs; that doesn't mean it's right, but it happens. In this day of comparitive equality, however, women don't sit idly by darning socks while their husbands tryst with floozies. They divorce their husbands - or if they really want to get even, they have affairs of their own.
But in those discreet days women just ignored their husbands' "running around" and worried instead over whether the flowers were delivered on time for their lunch party. They also had more serious matters to attend to - church, charities, their children's education. Mrs. Guggenheim, like other society ladies, was no silly, provincial miss ignorant of the ways of life and therefore she shouldn't be seen as a complete victim.
As to Mme. Aubart (I wonder if she was not really a Mdlle?) being "a bit of fluff," she was most likely that and more - but what a mysterious one. I'm intrigued by her and hope more will come out about her life and "career," if there was one beyond that of courtesan, though such a mode of business could actually be far more interesting to learn about than any singing job she might have had.
Randy