The Perfect Girlfriend by Karen Hamilton

Lily cannot let her ex-boyfriend, Nate, go. Determined to get him back, she gets a job as a flight attendant at the same airline that Nate works as a pilot for. For a few months she stays under the radar, since Nate had made it clear that he never wanted to see her again, although she still has the key to his apartment and frequently goes there while Nate isn't home. Still, Juliette (aka Lily) is waiting for the right moment to spring her surprise on him and making him hers again, no matter the cost. The Perfect Girlfriend is a suspenseful read, similar to The Last Mrs. Parrish and The Wife Between Us. It will be published next month.