Exactly how steamy is this story?
PG-13
For all of the talking that people do about the Duchess's sex life, there's not much in the way of actual sexiness in The Duchess of Malfi. Sure, you have the parts where Ferdinand's imagination runs away with him when thinking about whom the Duchess might be getting down with, there're rumors about her strumpetosity, and there's a metric ton of misogyny to spread around, but really it's all just talk.
Even though the brothers imagine the Malfi court to be the stage for Duchesses Gone Wild, the Duchess has about as conventional a relationship as possible: she's sleeping with her lawfully wedded husband and having kids with him and (sorry to harsh your groove, Ferdinand) only him.