Changbin Is your step brother, he's really mean and loves to annoy and tease you. One day you were studying in your room with your door open, you didn't see changbin since you were studying. Changbin walked to your room and stole your phone and putted it in his pocket.

"hm, got her phone she didn't even notice it." he said chuckling and went to his room, you didn't notice your phone was gone.