Bed Me, Duke by Felicity Niven

A desperate Scottish countess seeks lessons from a gorgeous rogue.

He can’t stand her fierce resistance to his charms. She can’t stand his dazzling good looks. But why bother standing when they’d both prefer to lie down on a bed together? Especially since neither has any intention of falling in love.
Captain Jack Pike leads a blissfully carefree existence as London’s richest and most notorious rake. Becoming the Duke of Dunmore would ruin his fun. He doesn’t even know where Dunmore is—Scotland, maybe? To add insult to injury, the savage Countess of Kinmarloch refuses to swoon for him. But why should he care? Jack only beds women married to other men, after all, and there’s not a man in the British Empire brave enough to wed the feral countess.
A countess in her own right, Helen Boyd must marry the new Duke of Dunmore to save the people of Kinmarloch from starvation. If only the troublesome Jack Pike would go away and stop torturing her with his handsome face, perfect male body, and shameless flirtation. On the other hand, Jack might be just the man to teach the woefully inexperienced Helen a thing or two about seducing the duke and luring him to the altar. And as part of her training, there would be the added advantage that she would get to bed the most beautiful man she’s ever seen.