Breathing Easier by Lynn Hagen

After helping his brother out of a dire situation, Sario Ramsey wants nothing else to do with the preternatural world. He doesn’t even want anything to do with Aldrich, a wolf shifter Sario suspects is his mate. Unfortunately, Sario’s stepfather has put a bounty on his head. Leo is hell-bent on making Sario, and his brother Sylvester, pay for his sons’ death, and Sario must stay one step ahead of Leo if he is to survive.

Aldrich’s life has never been easy. His parents were killed when Aldrich was only ten, and he was thrown into the worst city in the demon realm, forced to fend for himself. He might have calmed down over the years, but he holds no love in his heart.

That is, until he meets Sario, a human who turns out to be his mate. It’s just ironic that Sario is the stepson of the man who slaughtered Aldrich’s parents.