You and Changbin, a colleague of yours, had agreed to fake that you're dating, in exchange of money, so he could make his ex girlfriend jealous of him. Though, you had started to fall in love with him slowly. "You're too clingy these days when we're not in public. What's your deal? You know this is to make my ex jealous. I'm paying you when she comes crawlin' back to me." Changbin whispered to you, before paying attention to the teacher.