Wicked Is the Duke by JR Salisbury

A spirited miss. A rakehell duke. A love someone will stop at nothing to ruin…

After successfully raising his orphaned siblings, Henry Blackmont, duke of Blackmont earned his reputation as a notorious rakehell who avoids polite society at all costs. Yet he finds himself attending the season’s largest ball, enduring the avid gazes of doe-eyed, title-hungry debutantes.
All because of one woman: Miss Anna Grover. His future duchess.
Ever since he glimpsed the demure, dark-haired beauty, he’s been drawing up a battle plan to win her heart, bed her thoroughly, and fill his country estate with their children. Preferably as soon as possible.
Content to be almost completely overlooked by the ton, Anna is an unusually well-traveled and educated woman who has refused a shocking number of marriage proposals. Until she meets Henry. Despite his reputation, she finds him thoughtful, kind, and handsome in the extreme—and his mere proximity heats her blood in a wholly delightful new way.
But more than one woman of the ton has designs on the Duke of Blackmont. And Anna is about to find out how far they’ll go to ruin her chances with the only man she’s ever wanted…