A secret affair - Mary Balogh

Hannah Reid, born a commoner, has been Duchess of Dunbarton since she was nineteen years old, the wife of an elderly Royal to whom she is rumoured to be consistently and flagrantly unfaithful. Now the old Duke is dead and, more womanly and beautiful than ever at thirty, Hannah has her freedom at last. And she knows just what she wants to do with it. To the shock of a conventional friend, she announces her intention to take a lover - and not just any lover, but the most dangerous and delicious man in all of upper class England: Constantine Huxtable.

Constantine's illegitimacy has denied him the title of Earl, but otherwise he denies himself nothing. Lounging in a country house he populates with trollops, vagabonds and thieves, drinking deep from the goblet of his own carnal lust, he always chooses recent widows for his short-lived affairs. Hannah will fit the bill nicely. But once these two passionate and scandalous figures find each other, they discover it isn't so easy to extricate oneself from the fires of desire - without getting singed.