Dark Rivals by Penny Crane

“I know your weakness—me.”
The son of a powerful mafia boss. The daughter of a matriarch feared throughout the city. They were never meant to be together—rivals since they were born—but anything can change in the heat of the moment. If anyone finds out, it could mean war between the families. But some passions cannot be denied no matter the risks.
Nearly a century of harmony between four crime families. Calvos. Castillo. Rossi. Kova. Names that make you fear. Names that mean power. Names that mean blood. Peace between the most ruthless names in Chicago. But good things never last, do they?
Rivalries run deep. Not even eighty-seven years of alliances can erase the past.