Yeah…I wish they were a little more fleshed out too but since they are the side couple, I guess the author wanted to speed run their story a little bit and had to use hyobin’s cold and later his side hoe (his fuck buddy that ended up asking him out later and it felt so random) as just a plot device
I would have preferred if the author had made hyuk attempt to move on and try to act normal around hyobin. Hyobin now having gotten what he wanted realises that he actually doesn't want to be just friends with hyuk,it would have been more interesting development rather than trying to make hyobin feel ashamed of his past relationships.
Unpopular Opinion: i hated the side couple. Hyobin is a bigger red flag than dojae but for some reason,people tend to be more lenient towards red flag bottoms than tops.At least for dojae,you can rationalize his cheating by saying that he's on the spectrum so he took the boundaries set by euntae literally and that they werent even dating then ( i personally dont agree with this rationalization) whereas hyobin kept pushing hyuk away while at the same time not wanting hyuk to actually leave him. He chose to keep hurting hyuks feeling as an attempt to protect his own .If hyobin had been a top,people would have hated him. Also hyuk should have just moved on. I wasnt really convinced that hyobin loved hyuk romantically but it seemed more like that he was just scared of losing him . I would have hated this couple less if they had taken more time to get together and if hyobin was allowed to introspect his feelings for hyuk with clear mind rather than when he was sick.