Disease

You had a friend, you confessed your love to him, he said it wasn't mutual, but he loved you, he was just afraid to say it, and you got sick and now you're coughing up flowers. You remained friends. He texted you, "How are you?" You replied, "Not good, I'm coughing up blood." He wrote, "Are you coughing up blood?" You wrote, "Basically, come over and see, I don't remember what the disease is called." After a while, he came over; he has keys to your apartment, but you don't have keys to his. He saw you coughing up blood and flowers, and he understood that this illness was because of him, because it usually appears with unrequited love.