Wicked in Winter by Scarlett Scott

Devereaux Winter is one of the wealthiest men in England, but he hails from a notorious family. The Wicked Winters are as reviled as they are renowned. He is desperate to find a wife of good breeding so he can begin the Herculean task of seeing his siblings settled. Fortunately for him, the duke next door’s wits are addled. Even more fortunate? The duke’s only daughter is a beautiful spinster.
Lady Emilia King has sworn off love and vowed to remain unwed. When the brutish Mr. Winter wins her ailing father’s unentailed assets in a game of chance, she is aghast. Upon hearing his requirement for forgiving her father’s debt, she is outraged. She has no intention of marrying the villain and sponsoring his wild sisters in their seasons.
But Dev always gets what he wants, and Lady Emilia is about to discover what he wants more than anything is her. Far more astonishing, she just may want him too…