It is irresponsible to skip work without calling your job.
Craig works as a teacher and has a doctor's appointment coming up during class hours.
Craig wants to go to the appointment.
Craig asks a fellow teacher to sub his classes while he's at the doctor.
Craig assigns his classes busy work the day before, then goes to the appointment without notifying anyone.
The students are watched by an experienced teacher.
The students go wild without a teacher and cause trouble.