A Demon’s Trust by Catherine Lievens

Opposites really do attract.

Roque acts first and asks questions later. Since he’s kept Prince Berith alive since he started working as his bodyguard, he sees no reason to change that. When Berith pairs him with Dimri, his spymaster, Roque finds himself having to work with the most infuriating demon in Hell.
Dimri has spent his life working alone, planning his every move and staying three steps ahead of his enemies. It’s the best way to protect Berith, and the last thing he needs is a reckless bodyguard stomping all over his plans.
But when Dimri’s spy network is compromised, he has no choice but to trust Roque. As they work together to find the spy in the palace, Roque and Dimri discover that their differences might actually complement each other.

They’re drawn to each other, but their job is to protect the prince, not each other. Will they be able to do that? Or will they lose something they hadn’t thought they could have, especially not together?