
The way I would example his character is someone who lives and want what Jaein had in the past, his innocence of being in love. Yoon is someone who lives in the past and instead of moving on he hold on to it. He sees that Choi is using him to keep tab on Jaein, making him believe that Choi is still in love with Jaein(yes, but it became obsessive and possessive). Yoon doesn’t see Jaein’s suffering, but only thinks of his happiness aka his past when he was with Choi.
Yoon is so blind to see that Jaein is who he is because of Choi tortured and believes he’s doing good; basically he’s the friend that tells you it ok to get back with your toxic ex because he believe that he can change or it was just the moment and you guys look really happy before this one mistake(abuse).
I just finish reading the main story and before I proceed to read side story, I need to say this first. I feel so stupid to be curious about the reason behind secretary yoon action all this time. I dislike him.