Devoted Sinner by Charity Parkerson

King sees working for Bryson as punishment. Bryson sees it as winning.

Working for Bryson isn’t by choice. As one of the many men trained by an underground organization to be an assassin, King has simply been sold to the highest bidder. His job is to keep Bryson safe. Even though he has nothing against Bryson, a slave is a slave, and King is tired of this life. That doesn’t stop his immediate attraction, which grows stronger every day. Thankfully, King is used to going unnoticed.
While Bryson truly needs King’s protection, that’s not the biggest reason he brought King to live with him. He spent a lot of time with King’s former boss. He knows King isn’t safe there. Plus, Bryson enjoys pretty things, and he’s not above using every trick to collect them. Unfortunately, months of watching King has become an obsession. It doesn’t matter if they feel the same way. There’s still someone out there wanting him dead. Neither of them will be free as long as they’re always wondering if the other one is there because they have to be.

Devoted Sinner is the sixth book in Charity Parkerson’s Damaged Devils series. These are dark romance stories with crime lords, assassins, and sociopaths who find their hearts. They are best enjoyed when read in order.