You are wrong.
1. No one should be forced to disclose their sexuality until they're ready. I don't get how you do not understand that.
2. He confessed because he knew she was not even in love. She loves him too so that should've been a happy ending. But no.
3. She's mad because she thinks he slept with Mujin and is salty like she's this pure virgin.
4. She's too entitled and thinks the world owes her explanation and all the best things.
5. True, Seung ah is also at fault for having bad taste. He tolerated too much BS and his love persisted. "you deserve what you tolerate" so maybe they do deserve each other.
Again, SHE IS THE BAD GUY. A selfish sad girl victim wannabe scum.
ps. I assume from your name that we're both Jensetters but girl, we're not on the same page as this one.