Meh I'd rather she was more neutral than "dissatisfied", with the first few encounters being angry sex like Rosy giving a BJ for these first few bags of flour, then as she starts to compare sex with the MC with that of her husband, she comes to enjoy it... then let her notice how rare it is for her husband to give her attention and how lackluster it is compared to the new experiences the MC's is introducing her too, which in turn lets her excuse more deviant acts with the MC (after all he really appreciates/desires her).
Neglected housewifes don't tend to feel neglected until they have something to compare it too.