The narrow staircase in the apartment caused the boy and the girl to accidentally bump into each other while going up together.

Video The narrow staircase in the apartment caused the boy and the girl to accidentally bump into each other while going up together. , clip The narrow staircase in the apartment caused the boy and the girl to accidentally bump into each other while going up together. , The narrow staircase in the apartment caused the boy and the girl to accidentally bump into each other while going up together.