The False Shaman by Jordan Castillo Price

Being sold into slavery by the brothels was bad enough. Then I was handed over to an orc pretending to be a shaman.

One minute I’m fighting for my life in the hot springs while the old shaman works his magic, the next I’m property of his replacement. But something’s off about Droko—he has the muscles of a warrior, the confidence of a noble, and no idea how to perform even a single ritual.
I should be planning my escape. Instead, I’m teaching this hulking green fraud how to fake his way through ceremonies before we both end up dead. There’s just one problem: the more time we spend hiding in shadowy caves and whispering secrets, the harder it gets to ignore the heat between us.
As ancient prophecies, power struggles, and one very angry honor guard threaten to tear us apart, we’ll need more than clever tricks to survive.
When humans from the civilized lands find themselves claimed by orcs of the fearsome Red Hand clan, passion ignites. These stories weave together clan politics, ancient prophecies, and dangerous adversaries with slow-burn romance. The series follows unlikely heroes as they navigate treachery, cultural clashes, and unexpected attraction in a richly detailed world where survival depends on finding common ground.