The Windsors Series by Catharina Maura

"The Devious Husband" is the sixth installment in Catharina Maura's "The Windsors" series. This steamy and angsty enemies-to-lovers arranged marriage romance centers on Xavier Kingston and Sierra Windsor, who are business rivals. When Xavier notices Sierra showing interest in another man, he fears losing his chance with her. In a bold move, he proposes a merger between their companies, with one condition: Sierra must marry him.