Book 3 in the Nature of Desire series.
They call her the Ice Queen. At the exclusive BDSM club known as "The Zone," Mistress Marguerite is a legend. Tyler Winterman has been fascinated with her since he's known her, though the rules of their world say they shouldn't share more than mutual admiration. He is her male counterpart, one of the most powerful male doms practicing at The Zone.
Due to a computer error, Marguerite lacks the mentoring program stipulation required of all Zone doms, which includes spending a number of hours learning about BDSM from the submissive's perspective. Tyler considers it an act of fate that Marguerite chooses him to be the dom who helps her fulfill that requirement. He is convinced she is a "switch", a closet submissive, but the truth will be even more remarkable than the theory, changing their lives in ways neither of them anticipates.
Having no equal except one another in their skills at stripping a sub's defenses bare, these two dominants will turn their considerable talents on each other and discover that who is master and who is slave doesn't matter, not when two souls have found their mate.