Rich Mafia Leader

Reader is dating sanzu for awhile. But He noticed that Sanzu and Rindou are getting pretty close to eachother. One night while the reader is coming home late from a shift. He walks in on Sanzu and Rindou having rough sex... but not the hook up kind of sex.. Its the 'We've been dating for awhile and we love eachother' type of sex.
The reader is also a average boy but... he also has a kinky or horny side.
One day as he was running out of his house crying after seeing his boyfriend in bed with another male. The male's name being Rindou. He decides to wonder the streets alone and sees MIKEY getting shot. He tries to defend mikey but by the time he gets there its too late. He takes a good look at Koko's face and he immediately recognizes him. Koko and him work at the same restaurant and he really didn't know that Koko was a mafia leader. Koko and the reader are sworn enemies. They swore to never fall in love with eachother but what happens when Koko takes the reader hostage and they begin to fall inlove with eachother. Not only that but SANZU is trying to win the hostage/reader back.. Will Sanzu come out alive and win the reader back, or will it end up in a 4way relationship?