Born in Darkness by Amy McKinley

Destined to be king, Mafia underboss Stefano Rossi bides his time until the throne is his and he can claim the only woman he wants by his side. To show interest in her will place a deadly target on her back, but he can’t resist the forbidden Mafia Princess. In the shadows, they find each other, if only for a few stolen moments. Their relationship is full of risks and dangers, especially while his ruthless father lives. But he has a plan to change everything, and when they learn there’s a rat in the Chicago outfit, it’s time to act.
Emiliana Vitale fell in love with the one man off-limits to her years ago. Forced to keep their feelings for one another a secret, she craves so much more than their clandestine kisses. After clawing her way through hell and back from a vicious attack initiated by a rat within the Five Families, she has emerged changed, her darkness matching Stefano’s. She’s ready to unmask the traitor and take possession of the life she’s always wanted, one with the dangerously handsome Stefano, and she’s tired of waiting.
Her enemies are his, and when Emiliana’s life is threatened, Stefano takes matters into his own hands to ensure her safety. As they grow closer, so do their enemies. But he’s ready for them. Nothing will keep him from Emiliana, and he’ll slay anyone who threatens what’s his.