based on Byron’s poem, “Parisina” http://readytogoebooks.com/LB-Par50.htm.
The older man, Niccolo III d’Este (Marquess of Ferrara, condottiero, 1383-1441) now on a second repository of his seed. Has children from the previous one, including a handsome young man, Ugo the bastard, same age as Parisina, Nick’s current wife.
Parisina at first hates her stepson. Nick encourages them to get to know each other. They do but not in the way expected by dad; the two have become lovers–and for that they must die, by beheading.
At the time of writing Parisina, Lord Byron hadn’t had as full an understanding of Parisina’s fate as he did later in life. In the poem, he says no one knows what happened to her. Most accounts today, not that they necessarily mean anything, say Parisina also lost her head. Some of her attendants and other “unfaithful” women of Ferrara also at the same time are reported have had their heads roll thanks to Niccolo’s fury.
I used to live beside a man about the same age as Nick when this story takes place. His Japanese nymph turned out to be shagging his son. They eventually got married and moved to the island nation where Jimmy Cameron is moving.
Your own child making love to the spouse you think is yours exclusively. Typical human motif, for which heads have rolled.
Ezra Pound fans should recall that Parisina is Sigismundo Malatesta’s first cousin. Sigs’s first wife was his niece, Parisina’s daughter, Ginerva d’Este, who died in 1440. Some speculate Sigs murdered her.