
I just finished season 1. And this is deeper that I thought it is. From what I have gathered, in the past, Seo In and a group of students ganged up Yeongwoon and it may have been due to:
1. Yeongwoon wanted to break away from Seo In. We already know his obsession with Yeongwoon can reach at its limit. Seo In might have thought that if Yeongwoon fear him, maybe he will never leave him.
2. Seo In must have known that Yeongwoon like him. I think Seo In might still be confused with his feelings with Yeongwoon and he thought instilling fear to Yeongwook will give him the idea to forget about his feelings and will return to them just fooling around. I know it doesn't make sense cause Seo In started to get clingy with Yeongwoon but Seo In as character is senseless either so I don't care. I may be wrong in the future but I don't care cause now we know his mother decided to cover up the incident by giving them shush money. And maybe, this may also been the cause of his mother's anxiety attack.
I feel lightheaded. This is giving me headache. I'm dropping this shit