His Secret Sin by Sam Crescent

Diego Leoni is used to getting what he wants. He’s one of the best capos the outfit has to offer. Anyone who betrays the outfit, he kills. His first wife knows about that.
Belle Johnson is alone in the city, trying to prove her independence. Blinded in an accident as a child, she can’t rely on anyone. Now, abandoned in a nightclub by her friends, she has to call for help. And Diego answers, being the sweet, kind man, who helps her home.
Diego knows he can’t keep Belle forever. She doesn’t know who he really is, and there’s no way to tell her that the person she’s having sex with is also part of the mafia. Violence is in his blood, and yet, when he’s with Belle, the darkness fades away, leaving just the two of them.
The only problem is, he’s already engaged to another woman, one whom he doesn’t want. But he can’t let Belle go. The only solution is to get Belle pregnant and keep her in his world—without ever letting her know exactly who he is.
But secrets don’t stay hidden forever…