Seducing the Alien King (Galactic Courtship #21)

Valeria molds herself to fit any mission, making her the perfect spy and assassin. When Earth hires her to infiltrate the Sri'thaen homeworld, she jumps at the chance. The assignment is most likely a suicide mission. The type of mission she can't resist. It will be the ultimate test of her skills - cause chaos for the Sri'thaen government by killing those in power or gather intel. When she finally becomes one of the king's concubines, she sees her mission coming together perfectly. As Valeria grows close to the king, her heart slowly grows attached to a man who should be her enemy. With danger breathing down her neck, she knows it's only a matter of time until her deception is revealed.

Known as a bit of a playboy, Akkon has yet to claim the throne. He is king, but he hasn't participated in a single council meeting. Instead, he allows his councilors to create laws and guide their people. When a human sneaks into his bathing chamber, he sees a pretty face. Little does he know the human, Valeria, will infiltrate his mind and heart. She guides him to the throne and helps him become the king he always needed to be, but when her secret is revealed, can he get past it, or will it forever separate them?

No cliffhangers, no cheating, HEA guaranteed! Can be read as a standalone romance. Adira and Rak make an appearance from Seducing the Enemy.