Knight. Crime Lords, #4

Theirs was the perfect marriage...no, it had been. Right up until his husband Mao Omori, head fo the Omori-Vasilev Syndicate, became obsessed with expanding the Syndicate's power beyond the borders of Greertown. Hours spent pouring over maps and maing plans turned into days, weeks, and months of Jun being ignored. And he's had enough. Jun packed his bags, walked out the door, and didn't look back.
Didn't think it was worth looking back when no one was there to notice he'd gone. But being single wasn't all that great either. Drowning his sorrows night after night, Jun encounters a man who promises a fresh start. One night together that never needed to be repeated. No names needed to be shared. Except Jun isnt the only one hiding a secret. And Mao refuses to let his husband walk away... Knight is the fourth book in a dark mafia series filled with angst, violence, romantic drama, betrayal, and jealous rages, as the men of the Omori-Vasilev Syndicate fight to hold onto those htey love amidst a war with an unknown enemy.
The books are not standalone and must be read in order. Contains both MMM polyamory, and MM romances.