Fallen (The Fallen Saga Book 1‪)‬

Julie Anderson never wanted to leave her life and friends behind in Connecticut, but when her father gets a new job in Texas she discovers her destiny. When she meets the devilishly fallen angel, Nick Landers, her life begins to unravel.
Nick is different from the other boys and seems to have a crush on her. Julie soon learns that Nick has taken an oath never to fall in love with an earthly woman. Despite Nick's unhealthy obsession with her, Julie finds herself falling for him.