
you guys should know that in attaining "development", there are stages before that and its super obvious that seungho is on a stage wherein he is in denial of his feelings of Nakyum (flashbacks of his time with his friend saying "when have you become si possessive?") and that is a trigger for him to "agree" with his friends (But yeah so petty but what do you expect from a psychopath like Seungho?)
also, its obvious he went back to his old habits to prove a point to himself (that he didnt change bcs of nakyum) and it was even triggered when he discovered that it is bcs of In-hun that Nakyum is affected and somehow changed
in simpler words, Seungho is in tsundere mode and he is yet to accept his feelings since he is aware of Nakyum's feelings for In-hun
that scene where jonathan is asking yuna to leave together in front of sophia is fucking hot