Responses

Junseok has only ever been an fboy and he assumes that because he feels more deeply inside it must be obvious to others that he's sincere; Gunjoon feels inadequate and is too scared to ask for clarity. Those are pretty realistic mistakes to make especially in a first relationship -- that’s why a lot of them don't last!
The miscommunication is frustrating, sure, but everyone seems to be forgetting these are college students and neither of them has been in a relationship before. The solution is obvious to us because we already know both sides but these guys are clueless relationship idiots, it's normal that they're not handling it well