The Doxy and the Duke by Caroline Lee

Lady Raina Prince might be the daughter of a powerful Highland earl, but polite society wants nothing to do with her, thanks to the illegitimate son she bore five years ago. She wouldn’t trade wee Ewan for all the parties and musicales in the world, but when her old teacher, the Countess of Fangfoss, invites her and her five dearest friends to a summer house party, Raina can’t resist the chance to see her chums again. She brings Ewan along as a reminder to herself, and everyone else, that she’s not going to play their silly matchmaking games…and it works.

That is, at least until the day she takes her son swimming and meets a handsome and mysterious stranger enjoying the water with his son. What harm could there be in having some fun with a man who refuses to tell her his full name or rank? And if he thinks the worst of her…well, that could lead to some fun too!

The Duke of Cashingham has no time for frivolities, but he’s given his heir, Matthew, his word that he’ll make an effort to find a second wife. Thus, he has made a point of attending the Fangfoss affair to meet each eligible lady, and has been disappointed. But when he meets an intriguing—and obviously easy-virtued—Scottish lady by the river, he sees no harm in suggesting an informal liaison.

But the more time Cash spends with her, the more he realizes Raina is exactly the sort of woman he wants for a wife. Too bad a duke can’t marry his doxy… It’s up to mischievous Ewan and studious Matthew to convince their parents that, not only are the two adults in love, but they have a chance at their very own Happily Ever After…before the end of the house party!