The Duke in My Bed by Amelia Grey
Bray, the Duke of Drakestone, considers himself the ultimate bachelor. Thinking marriage to be nothing but an irksome responsibility, he has no intention of settling down. Until one rainy night, a Viscount's fatal accident leaves Drakestone bound by a promise - to marry the Viscount's sister. He's counting on Miss Louisa Prim to be an aging spinster-but when he finally arrives on her doorstep, he finds a stunning, fiery beauty...Louisa has no intention of marrying Bray Drakestone. With no need for a husband and appalled by his assumption that she would rush into his arms upon his proposal, Louisa thinks she can expel him from her life, despite his roguish charm and good looks. But with Drakestone putting his best efforts into seducing her, he becomes harder and harder to resist...