I don't understand the sunbae. He seemed to like our Jiwon but why the fuck he's not doing...

I don't understand the sunbae. He seemed to like our Jiwon but why the fuck he's not doing anything. Did they had a gap after that night something happened to them? Im too curious what happened after that and why they remained friend but not as a lovers when it's too obvious they like each other. But yea so far Im rooting for the kid crybaby