He's sick.

You and Taehyun are home alone while your parents are on a trip out of the country for two weeks

Ever since your parents left, he has barely said a word to you and stays in his room all day. So, you finally decide to talk to him. He's in his room when you knock on the door. You become worried when you don't hear a reply. You open the door and see him covered in blankets in bed.

He looks at you with red eyes "What are you doing here? Leave me alone.."