Heatwave

Manny, a member of the gang "Seven Sins" and a police informant, finds his partner a victim of a serial killer. Unable to shake off the shock of his partner's death, Manny is forced to renew his relationship with Sean, his normally awkward partner, at the boss's behest. To make matters worse, a police officer he's in league with asks him to investigate Sean. With no choice, Manny decides to seduce Sean in the most confident way possible...

"You said you'd never do it with me again... but something smells very fishy. What could it be?"

(Source: Lezhin, translated)