The Assassin, the Djinn and the Hundred Year Wish — Stella Price

As a Djinn, the most powerful race of genies, Nicodemus Marsh is sent in to deal with a fiery Janey Duvall after she refuses to help the exiled demon prince get rid of the problems in a business endeavor in the east. Oozing with sex appeal, Nicodemus begins a seduction Janey can barely resist. After a very erotic encounter, Janey finds out she's bound to Nicodemus, and has three wishes to make. The bargain? Three wishes, and in return, she's his sexual slave for 100 years.