He was kinda attracted by Soohyun's personality or nature. And his gaze always lingers towards Soohyun. That's why and he kept his button in his drawer since then. It's an indication he had something for him and throwing away could be taken as he moved on.. that's just my pov though. Others can have diff views...
Yeah, he didn't hit on him or flirt but there was tension between them. When Soohyun asked for a neck bite and stuff. It's just that sunbae is the type who doesn't focus on things he isn't interested in.. They might not be romantic feelings but just subtle curiosity about him.. Since this is a manhwa and open to many viewpoints, and those are my experiences which I had reading the manhwa. Yours could be diff (^^)
Omg omg omg It's finished.... It's so Cute. His hyung is damn freakin Hot and easygoing and Smooth talker . I want him duh!!
Anyway Minseok my babe, throwing away Soohyun's button indicates he's moving on from those little feeling he might've had for Soohyun..