The Mark of the Vampire Queen — Joey W. Hill

Full servant. With his new title, Jacob must attend to Lady Lyssa's every need, venturing into a world of passion darker than he's ever known. As a vampire hunter he wasn't prepared to embrace a world where humans are sexual commodities, but he has adapted. Now he finds the integrity of his soul challenged as he serves his Mistress's needs as fully as he services her desires.

He loves her, though other servants warn against giving her his soul. Everyone knows that Vampires have no regard for humans, so why would a Vampiress bother treating a mere sex toy with respect? But Jacob knows a human servant is far more than that. His Mistress needs a warrior, a friend and a lover. A man who will serve her in all ways, even if he has to betray the priceless treasure of her love.