They're not just romantically interested in each other, they're also best friends and you can see that in the way they interact. People are hating on present Kyubin, but i think the reason for his behavior has already been explained, they're in love and Seungtaek has made a move on Kyubin, but Seungtaek is in denial and their relationship isn't progressing so Kyubin is desperate. I think people are misunderstanding the scene where Kyubin beats up Seungtaek, Kyubin KNOWS how strong Seungtaek is and that he can take it, i think he beat him up to take the blame for the fight, like he has 2 times now in this flashback. Seungtaek is still the model student, he was saving his reputation by saying "i was just beating him up". I think the people judging him are really just suffering the effects of being outsiders looking in as the two of them seem to have an understanding of each other. It was okay to Seungtaek, he didn't fight back. Probably because he understood.
They're not just romantically interested in each other, they're also best friends and you can see that in the way they interact. People are hating on present Kyubin, but i think the reason for his behavior has already been explained, they're in love and Seungtaek has made a move on Kyubin, but Seungtaek is in denial and their relationship isn't progressing so Kyubin is desperate. I think people are misunderstanding the scene where Kyubin beats up Seungtaek, Kyubin KNOWS how strong Seungtaek is and that he can take it, i think he beat him up to take the blame for the fight, like he has 2 times now in this flashback. Seungtaek is still the model student, he was saving his reputation by saying "i was just beating him up". I think the people judging him are really just suffering the effects of being outsiders looking in as the two of them seem to have an understanding of each other. It was okay to Seungtaek, he didn't fight back. Probably because he understood.