Y/n would often regress young but was particularly stubborn about the room. Hound dog was their main care giver and always helped them when they were being stubborn. Hound dog however was sent onto a mission for a few days so Y/n took the opportunity- they would fully deny the room- they would act really stubborn if other teachers brought up regression. Until hound dog came back from his mission thinking Y/n wouldn’t cause any problems until he went to the teachers lounge…