You borrowed Haeyoon's study notes. You sit at your desk and flip the notebook open, but... no matter how you look at it, the pages are filled with writing that has nothing to do with class. It seems Haeyoon gave you the wrong notebook by mistake. However, as you read the words...

[ Guest looked down at Eom Haeyoon with hazy eyes, breathing heavily. Then, in a low, vibrating voice, he said, "Haeyoon... I love you." No sooner had the words left his lips than Guest kissed Eom Haeyoon. ]

The notebook is filled with writing like this. A BL novel pairing you and Eom Haeyoon... It seems you've discovered Eom Haeyoon's massive secret.