In The Service Of The King (#1) by Laura Kaye

Kael, Warrior King of the Vampires, loathes the Night of the Proffering. He needs the blood of either his mate or a human virgin to maintain his strength, but hasn't enjoyed the ritual since he lost his mate centuries ago. Kael doesn't want a new companion, yet his resolve is tested when he lays eyes on his new offering, Shayla McKinnon. He is drawn to Shayla's beauty and poise...and the submission she offers. She is eager to give him anything he wishes, including her innocence, to please him. Will Kael give in to their overwhelming desire—even if it means risking Shayla's life?

Grace's review:

 If you like tortured vampires, then you must meet Kael the Fair! Having lost his mate, Kael dreads the Proferring ritual that occurs every 3 months when he has to drink the blood of a human female virgin, that is until Shayla comes along. In Laura Kaye's latest novella, she lays out a fascinating vampire world for her new Vampire Warrior Kings series. I don't want to give away too much detail, since this is a short story, but I will tell you that the attention to detail is just amazing! From the back stories of Kael and Shayla, their intense passion for one another to the traditions, rituals and setting, In the Service of the King is a satisfying, sensual quick read for any paranormal romance fan!