Dad wouldn't mind: a tragic incest story with a stepmother

Cory's husband died, leaving her with her adult stepson—a tragic situation, but life goes on. Cory turns to religion, while her stepson, on the contrary, begins to constantly fantasize about incest with his stepmother. One day, he can't take it anymore and confesses to her. Cory is against it, but the words "Dad wouldn't mind" trigger her. The stepmother sheds her image as a widow and enjoys fantastic sex with her stepson.