Well to point it out, in iltak's pov Hyunwoo showed MORE emotions in case of liking iltak which made iltak pay more attention to hyunwoo, since hyunwoo is more into blushy moments things like that and clearly it gave him the upperhand in iltak's mind when it finally comes to choosing.
Imagine if hyung-joo expresses his feelings more with his words instead of expressing it with harassment

Losing Hyung-joo made me cry bruh, he changed so much.. Those scenes where he said his goodbyes.. Fuck!!!!! I MISSS HIM SO MUCH I WANNA BE HISS