ONE-NIGHT MISTRESS...CONVENIENT WIFE (Harlequin comics)

Three years ago, Natalie was treated like a child and dumped by Christo, a handsome lawyer, when she was working as a clerk at his law firm. She's grown up since first becoming infatuated with his kisses, and she thought she'd gotten over him—but now they're working together, and the two of them find themselves sharing a bed again. Just when Natalie is balking at the fact that the only requirement of their temporary relationship is that they won't ever get married, Christo makes a cruel request... He wants her to pretend to be his fiancée to please his dying grandmother.