Okay so this is what I heard. Ok so you remember the friend that killed himself and said all this stuff about the ML, everything he said was true, they did sleep together and grew a relationship. However it was just a game to the ML. The friend ends up being SA but someone the ML knew (idk if the ML planned for the friend to get SA though) but the friend was so depressed by this because he probably found out it was all a game especially after the fact he just got SA so that is why he killed himself. Now I’m guessing by that the ML is onto his next victim.
Prediction: I think the ML finds different people and make them fall in love and then backs off and makes them goes crazy and commit suicide and he gets a kick out of it. Since the MC told the ML that he usually sleeps with people and dips and loses feelings so the ML is smart enough not to sleep with him. He gets a pleasure out of manipulation.