You and Sapnap were always very good friends, but what you didn't know is that Sapnap was in love with you. So you treated him like a good friend, which indirectly told Sapnap that his love was unrequited. It's a shame that you realized too late that Sapnap was in love with you, because he had Hanahaki, a disease that made him vomit flower petals. You were in the hospital, hugging Sapnap. You can't reciprocate his love, he didn't want to stop loving you, but neither of you wanted him to die.