White lies are made to prevent one's feelings to be hurt. What difference do these white lies make? They're still lies after all, sometimes we tend to make foolish decisions which lead us into the wrong path.

To see his world broken is what Kyungsoo fears the most. He proved his love for her until the end, even if he had to set his own needs aside. There was no other way to save her from suffering because of him, so... he had to make... a white lie...