Sorry but what's immoral about portraying a woman as being an active agent in a flirtation/affair that she seems to enjoy? Such things in the 1700s were not looked upon the same way as we look on cheating today. People having lovers and affairs in high society was tolerated. Even the King had a very well known and powerful mistress who was actually on good terms with his wife.
Are you implying that women are only ever poor passive victims of manipulative cads?
She's not even wearing a wedding ring, so for all we know she's not married and she's merely an unmarried coquette enjoying her power over two men at once - one who is her happy "servant", and one who is literally bowled over by the power of her sexuality. If that's the case there's even less to be offended by.
Also are you implying that the only person one is supposed to identify with in the picture is the man on the left? What about the woman herself? She's the one my eye is drawn to.