Never Doubt a Duke by Maggi Andersen

Lady Nellie Dountry, and Charles, His Grace, Duke of Shewsbury have had their hearts broken in the past. Neither is prepared to chance love again. When they are compelled to marry because of an agreement made long ago by their fathers, they are both determined to resist falling in love. Convinced that it’s mere desire which draws them together, both are surprised by their jealousy.
Nellie finds Charles irresistibly attractive, but other women do too. They circle like sharks. Aware that Charles’s former fiancée who had broken his heart some years ago is now a widow and on the hunt for a lover, Nellie struggles to trust him while she fears she is falling in love with him.
Charles was more than pleased with his choice of bride, but he wishes she wasn’t so difficult to understand. One minute she’s hot for him, the next as remote from him as a chalet in the alps. Why he wants to get close surprises him, he planned for his marriage to be little more than one of polite indifference. But Nellie is so dashed beguiling!