Cam and the Conqueror by Honey Phillips

He made a bargain. She was the payment.
Torn from her quiet life on Earth, Cam doesn’t expect to end up enslaved to an alien ruler. But even as he trains her to submit to him, she begins to see through her master’s cold facade. While her body learns to surrender, her heart learns to love.
Exiled by his people, Kievan Rus has fought to establish his place in the galaxy. The space station he rules with icy control is the outward symbol of his success and it means everything to him – until a beautiful woman challenges his restraint. Her warmth eases the cold he has felt for so long.
But Kievan has promised a trained human female to a member of the Royal House. If he fails to deliver, everything he has struggled for is in danger, including the lives of everyone on board his station.
Can Kievan abandon everything he has built? And if not, can Cam’s love survive such a brutal betrayal?