Nakyum should tell Seungho what happened to him. Seungho is the reason why he got kidnapped, so the least he could do is keep Nakyum safe and take responsibility to everything that happened to Nakyum because of him. Nevertheless, to be kidnapped without anyone knowing and be threatened like that...I understand Nakyum. Most people would've done the same in that situation.
Nakyum should tell Seungho what happened to him. Seungho is the reason why he got kidnapped, so the least he could do is keep Nakyum safe and take responsibility to everything that happened to Nakyum because of him. Nevertheless, to be kidnapped without anyone knowing and be threatened like that...I understand Nakyum. Most people would've done the same in that situation.