Galen by Jaclyn Osborn

Simon just wants to run his antique shop in peace.

But then he finds a small mysterious box that’s (probably) haunted, and his shop is broken into by the hottest man he’s ever seen who then steals said creepy box.
Now demons are after him and his only hope is to trust the tall, muscled, combat-boot-wearing thief who claims to be the son of a fallen angel.
Galen is charged with protecting humanity from dark forces. Cursed with Wrath, he’s hot-tempered and spends his days fighting demons and trying not to kill his six brothers when they irritate him.
His number one rule? Never fall in love. But then he meets Simon, a clumsy human who asks way too many questions and is—unfortunately—a total demon-magnet, and he starts breaking his own rules.
What’s inside the box, and why do the demons want it so badly? One thing is for sure… Simon can kiss his peaceful, ordinary life goodbye.