Kiss the Scoundrel Farewell. Once Upon a Widow

Miss Margaret Flemming marries out of duty only to find herself in the center of a scandal. Her husband, Baron Drake, dies in a duel over another woman. With no children and no desire to be shackled again, Meg decides to enjoy life as men do. She will be the other woman instead of the wife held captive by the whims of a man. Simon, Lord Hayward, a dutiful son with no fantasies of love, agrees to marry a wealthy heiress to plump the family's coffers.
His father, in love with his mistress for decades, sets out to find the same for his son. Simon scoffs at the idea, but when he meets an alluring courtesan at a masquerade, he finds himself smitten. In a twist of fate, the masks come off, and Simon and Meg realize they met years ago, sharing a kiss in a duke's garden. Their secrets come out: She is no courtesan, and he is betrothed. After the viscount confesses his love, the baroness flees for the safety of the countryside. As Lady Drake begins to doubt her scheme of being a paramour, Lord Hayward wonders if he can be happy with a wife who is not Meg and seeks her out.
But his search only reveals danger lurking in the idyllic English hills, and they soon learn the past has consequences no matter who you pretend to be.