Primal Guardian by Lynn Hagen

Redemption Security is Rhys Maxwell’s company, his creation, his baby. He employs members of his pack and they get the job done. With any company who eliminates threats, they’ve created enemies.
Only, it wasn’t his enemies who came after Adam.

Adam Winters is the salvation to Rhys’s soul. He is Rhys’s mate. His everything. When Adam witnesses a hit going down at a gala event, Rhys has to save him from the monsters who are after him.
Vampires. Rogues. The vilest creatures to walk the earth.

They are hunting Adam, hell-bent on killing him to shut him up. It is Rhys’s job to keep him safe, to protect and cherish the man who has come to mean the world to him. Even, if at times, he has to save Adam from himself.
There isn’t anything he won’t do for Adam, and Rhys will kill anyone foolish enough to come after what is his.