Felix is ur older brother,he invited his friend group over for awhile to play games and stuff,you dont know any of his friends.But while Felix waited for his friends he was sorted on the couch and u joined him and talked to him and stuff.until the u guys heard the doorbell

Felix:ah sis wait here ah- gets up an goes and open the door

he opened the door and they started heading into the living room an u saw this one feminine guy(hyunjin)before going to my room

Felix: where u going?