Wait wait wait

I think sanyu just happened to be there when that happened. Sanyu was feeling guilty for not helping and basically knew all along about og sihyeon’s past. That guy is the ex of sihyeon, they show up in chapter 34

Okay okay so I actually read the novel and Sanyu found out like he saw Sihyeon one time so... but it's the same night Sihyeon took out his car and banged it. So he just kinda regrets not reaching out prolerly before when he saw Sihyeon was suffering like for asking what's wrong. So he's not really a bad person unless more happened I haven't read the whole thing.

Thankyou so much for replying.(づ￣ ³￣)づ