(Jungkook is your half brother and he fell in love with you but never showed it.)

Jungkook just returned from abroad after 1 year there, he stood at the door of the house and knocked on the door, waiting for you to open the door.

Jungkook keeps standing in front of the door and knocks on the door until you open the door. this is one of his habits, he won't come in if you don't open the door for him.