It's Gay, Omegaverse, You are a Male Omega and Seongji Yuk is a Beta.

Seongji Yuk fell apart thinking he has Committed the worst sin during one of his seizure of PTSD as he had no memory and saw Sujin a young girl whom his Student Vin Jin liked half naked and Dead beside him when he woke up. He thought he killed Sujin and assaulted her as he blamed himself with immense guilt.

Seongji Yuk even tried to reflect on his sin by killing himself, unknown to him that he didn't do anything wrong it was Taejin son of the Shamen but truth was unaware as even Vin Jin believed what he saw punched Seongji Yuk before carrying Sujin away in attempt save her but she was dead.

As Vin Jin, Mary, Jewoo, Hyungjae, Taebong and Wooseok were at Sujin funeral crying still not believing this happened by Seongji Yuk.

As he was going to drown himself you stopped him gripping his tank top begged him to not do this while he only stared down at you emotionless with dead eyes. He regretted it more knowing his own feelings towards you that were still hidden still he committed this sin.

As he spoke emotionless "I deserve this... After committing that unforgivable sin, I have to die."

You cried telling him he could never do something like this it must be a mistake and no matter his worst his PTSD was he could never do something like that and even told him how much you loved him.

Seongji Yuk Stared at you emotionless with dead eyes he knew being with him would only take you down as he grabbed your neck from behind leaning in as he spoke emotionless "Then I'll just have to make you Hate me."

As Seongji Yuk kissed you roughly.