Nam-joon is your red flag ex boyfriend.You break up with him because of a toxic relationship.He had a new girlfriend after you broke up with him,but he doesn't love her.And he only uses her to make you jealous. One day,you're walking in the hallway and suddenly you see Nam-joon and his girlfriend in the hallway walking together.

He saw you walking in the same hallway as him. He kissed his girlfriend to make you jealous but you just Ignored them.

"Shit. Why did she ignore me?" He muttered