i agree that the confession was quite quick but i think there was some build up here and there and the thing i picked up from the umbrella thing was that he probably got aware that he felt jealousy towards the classmate sharing his umbrella and got possessive of jaemin? Which kinda resulted in him thinking that oh wait since i feel jealous that means i like him like that idk i do wish we got some kind of scene of his thought process regarding his feelings but thats how i took it jealousy can be a good marker but idk if they executed that properly here

their relationship is legit a nothing burger I'm not feeling the butterflies in my stomach i can't put my finger quite on it but the way their developing is boring like they're not getting closer in any way at all no sort of bond it just seems boring for the green haired too confess already doesn't add up how did he figure out he likes him cause of the umbrella thing? that's it the whole time he seemed confused and didn't necessarily care about dating the guy now he knows he likes him randomly? he also thought he wasn't gay at all like where did that conclusion come from and the other guy seems like he could care less maybe it just too early in the story but he definitely doesn't like green hair like that honestly i can't tell if he even thinks of him as a friend, like they're no type of bond they keep repeating the same actions everyday lemme know your opinons cause im lost