Forbidden Sins by M. James

He’s protected me all my life. But the only thing he can’t protect me from is himself.
I’ve been raised all my life to be the dutiful daughter of New York’s most powerful mafia boss. Protected by a man who has been my bodyguard since I was eighteen, I’ve never had anything to fear, or wanted anything that I couldn’t have.

Until a job gone wrong robs me of my brother, and the only person I can turn to is the man I’ve been trying not to want for three years…and shouldn’t love.
Now the only remaining child of the Gallo family, arranging a marriage for me becomes my father’s top priority. The man he chooses for me is powerful, wealthy, connected—and cruel to the core. When a desperate moment sends me fleeing in the arms of my bodyguard, I’m forced to confront a desire that I should never have allowed myself to feel—and a forbidden love that defies every rule I know.

I’ve never been allowed to choose. But if I could, I’d choose him.
Even if he’s forbidden. Even if it’s a sin.