Devil in the Elevator by Laura Christopher

Valentina Borroni never knew how one single moment in time could change her life, forever. Stepping into an elevator with a man she named Diablo, the Devil, did just that.
Noah Hartman, with his wicked tongue and inappropriate words he set her very soul on fire.
What happened next neither of them could have predicted. All they had in the world was one another. That, well, that was almost the scariest out of everything they had to face.