i'm not too mad tbh. its clear that hyesung is just really impatient. hyesung himself had really late development, so he's rushing to finish school. i think hyesung feels worried that byul might end up the same way as him, and just wants byul to grow up better than he did :(
this is definitely a big misunderstanding lolol bc if it somehow isnt and that actually is sunghyun WE'RE ALL GONNA CUT HIS DICK OFF
If it was a misunderstanding why did he lie about not being in Japan