Sweet Temptation. Sweet Series, #4

Bad boy Kaidan Rowe has never wanted for anything-money, popularity, musical talent, beautiful admirers.but seducing them is part of his duty as a Nephilim, a servant to the demon Dukes. As the son of the Duke of Lust, Kaidan has learned his father's ways, becoming a master of passion, a manipulator of chemistry. Disobeying his father would mean certain death, so thankfully for Kaidan, he's good at his job, and he enjoys it.
Until he meets Anna Whitt. Sweet, smart, feisty, and inexplicably good-the one girl seemingly immune to his charms. The daughter of a guardian angel and a demon, she has a certain power over him, one that makes him wish for more than he's ever deserved. Determined to save all the Neph from their dark lives as the influencers of sin, Anna joins forces with Kaidan to overcome the demons' oppressive ways.
Their relationship is as tortured as it is passionate, causing Kai to undergo his toughest and most dangerous test yet: a battle of the heart. Full of chemistry and high-stakes drama, this companion novel, told from the point of view of love interest Kaidan Rowe, is darker and hotter-the cherry on top of the Sweet trilogy.