Mistress Wael wanted this slave to eat her shit and so she did all she could to make it happen. She forced him to do it because she knew that if she did not, he would not do it. The mistress made it clear that if he did not eat her poo, he would have himself to blame for what she would do to him. He ate it so as not to find out.
Mistress Wael had helped out this guy and she did not expect anything in return. She did not even want him to be thankful for it. The guy went his way and she forgot about it. But he came a few days later for another favor and he talked as if it was his right. She was so pissed about it that she turned him into a shit slave and made him eat poo as punishment.