The Duke of Deceit by Anna Harrington

No good deed goes unpunished…and no blackguard unloved.
Lucien Grenier, Duke of Crewe, prides himself on his reputation – selfish, black, and wicked. Or, at least, that’s what he wants everyone to believe. What better way to keep society from discovering his secrets? But when rumors arise that he is doing good deeds for charities, children, reformers—even nuns—he has far more to lose than his wicked reputation; he might just lose his dukedom.
Jessamyn St Claire is determined to hit Lucien where it hurts most—his black reputation. Eight months ago, he ruined her sister, and now Jess wants retribution. Her plan? To take Lucien from rakehell to respected peer unless he marries her sister. But as Jess works to rehabilitate his character, she discovers that Lucien’s bad reputation is mere pretense. The more she uncovers, the more she learns of his goodness…and the more he captures her heart. Soon, it isn’t Amanda whom Lucien wants to marry but Jess.
Little does she know that there’s one remaining secret with the power to destroy them both…