dude thought they were in a relationship and was pissed sunwoo cheated gosh he's both bipolar AND delusional
he never had a crush before. So it's understandable. It happened to be. I didn't date in my teens, and I even thought I was asexual. Then I got a crush and felt like was a teenager again.
yoonsung definitely knew jiyoung was a guy back then didnt he? that could only explain a lot of his actions
LET THEM GET MARRIED IM ABOUT TO LOSE MY SHIT