After telling Porchay that he was only tutoring him and being with him to get more information about his brother (Porsche). He deeply regretted it as he does love Porchay

So after trying everything possible to apologize and talk to the boy, such as call, send him a video of himself singing (his a singer) or even saving him from a bad influence. Nothing

Porsche is dating Kim's elder brother, Kinn (the next leader of the main family [they're mafias]). So they're father instructed that both Porchay and Porsche move in.

Kim was aware of this, but he moved out years ago, so it didn't affect him and didn't care.

Kim was coming over for his monthly family dinner. The house was empty... They must have gone out