A Regency Duo by Carole Mortimer

Indecent (Regency Lovers #1) by Carole Mortimer
Impoverished Miss Emma Harris can hardly believe her good fortune when Adam Stirling, the handsome and imposing Duke of Hawkwood, asks her father for her hand in marriage.
However, she feels thoroughly humiliated when she attends a masked ball that very same evening and sees Hawkwood in a compromising position with a married woman. A very compromising position, in fact it is positively INDECENT.
Angry and upset, Emma confronts Hawkwood with what she saw, accusing him of only wanting to marry her as a shield to his affairs with other women. Accusations the duke immediately disproves.
Half in love with the arrogant Hawkwood, Emma is devastated when she learns the real reason he asked her to marry him. But if Emma thinks Adam is the type of gentleman to meekly accept her rejection, she is about to learn exactly how INDECENT he can be when he wants something as deeply as he now wants Emma.

Prince Of Scandal (Seduced by Scandal #1) by Angelique Armae
A lady in need of a scandal…
To keep up her secret work of rescuing street urchins from falling to ill repute, Lady Eliza Littlefield must escape her pending marriage to the cruel and very puritanical Earl Meyock. Unfortunately, only a ruined reputation will give her the results she’s seeking. And it must be a most damaging event such as slipping into a brothel and being found out. But when she accidentally lands in the bed of Freddie Baine, Countavia’s most notorious royal, the only person needing rescuing is herself.
Entraps the one prince who can’t afford another sin…
As the youngest son of King Bertram II of Countavia, Frederick Arthur Louis David is a prince with a problem. Not only is he working with his six brothers to track down and expose the realm’s underground anti-monarchists threatening to bring down the Crown, but he’s also on the hunt for the kingdom’s most notorious enemy–a cold blooded spy who is murdering Countavia’s most prominent peers. Which is why the last thing he needs is to be saddled with a wife. Especially one as wild and as unpredictable as Lady Eliza Littlefield.
But when he’s found with her in his bed at Madame Harpcourt’s–a safe house being used to conduct his mission under the guise of a brothel–he has no choice but to reel in the troublesome Eliza. Which poses problems in itself since he’s secretly been attracted to the woman since they were children.
But with a raging mad earl on his case, his covert mission on the brink, and a killer on the loose, what choice does he have? Keeping Eliza safe is a must. If only he knew he could keep her safe from himself–Countavia’s notorious PRINCE OF SCANDAL–the situation might not be so sinful.