Carnal smile on Kai, made me think it suits your story Kyanite69!

Kyanite69's story (for mature reader, be aware of the trigger warning !) : https://www.asianfanfics.com/story/view/1462663/the-accidental-demon

Editor's story : https://www.asianfanfics.com/story/view/1465268/the-three-of-us