In training her to become the matriarch, ML makes the unprecedented move of ordering Chastity (the good child) to mete out the discipline for Credence's latest screw up. Chastity doesn't like hurting people, tries to make it easy on him. Things maybe get a little weirdly heated. Ma catches them, decides she will demonstrate proper discipline technique...on Chastity instead...and Credence will be force to watch.