Sinuiseongsirui Wonchik

Prosecutor Baek has built his career by manipulating evidence and witness testimonies with the help of a gangster. His success catches the attention of higher-ups in the prosecution, who now want him to clean up his act and arrange a marriage with a woman from a respectable family. Seeing this as the perfect opportunity to discard the gangster who has been clinging to him, Baek accepts the proposal. However, the gangster - who has long harbored feelings for Baek and aided him in his illicit dealings - feels a deep sense of betrayal and rage upon hearing the sudden news. Now, with resentment festering, their once-covert partnership threatens to unravel in ways Baek never expected…
(Source: Lezhin US)
Note: Part of Lezhin's SS Short Story Collection (SS 단편선) or the Depraved Collection in english. Chapter count also contains prolouge.