Doku ni Kuchizuke

Mashimo, a former police officer, now works as a handyman, taking on odd jobs that often involve dealing with “demi-humans”—people with animal-like traits. One day, on his way back from a job in a city where demi-humans live, he reunites with Crow, a snake demi-human who once helped him in the past. Mashimo finds Crow crouched down, looking weak and exhausted, and tries to take care of him. However, as a snake demi-human, Crow has a certain instinct: when his body grows cold, he must warm it through sexual contact…?! Pinned beneath Crow, the two end up spending the night together. Mashimo assumes it will be a one-time thing—but it seems Crow has taken quite a liking to him…?

(Source: Core Magazine, translated)