A chastity slave is required to complete a course of ass-to-mouth interval training. The slave must ride a dildo until the interval timer sounds, at which point it must get on all fours and repeatedly deepthroat the dildo that was just buried in its ass. It must slobber and get face-fucked by the dildo until the timer sounds again, signaling that the slave must resume pounding its ass with the dildo. The slave will repeat this cycle over and over, commanded by the interval timer.