You may say that he was unattractive to her, and that, as she was splendidly kept by the duke, she would be more likely to choose a man who was attractive to her, if she were to take another lover.
Vous me direz qu'il lui déplaisait et que, comme elle était splendidement entretenue par le duc, pour faire tant que de prendre un autre amant, elle aimait mieux un homme qui lui plût.