
Eyyy I can shed some light on this (spoilers below obv)
So Soohyuk really admires Jiwook despite being mistreated by him and acts as his only "friend". It's worth noting that he's the person Jiwook wants most to keep the photos away from. Regardless, he still gets involved when Jooyeon coerces him to give him the contact info of the rapists in order to send them after Jiwook. Jooyeon then shows him the photos after the gang rape incident, which Soohyuk feels guilty over. He doesn't tell Jiwook that he knows due to this guilt but it's implied that he also got off on the photos and that adds another layer to their relationship. He wants to save Jiwook but he's too scared of upsetting Jiwook or incurring Jooyeon's wrath so he's pretty much a useless bystander whose probably the most "normal" of the cast.
Can some1 spoil me if fox guy is a good bad or neutral guy lol