This guy was gullible and he was made to endure and experience a lot of cruel things from these mistresses. They turned him into a human toilet and they made sure that he ate their shit and drank their pee. He did not have a choice but to do what the mistresses wanted. He had been tricked to think that they were trying a new way of foreplay but he ended up degraded and there was no foreplay.
Goddess Wu wanted this guy to do and to obey her without question and since he did not, she had to find a way to make him do that. The mistress did this by forcing him to eat her shit. He was shocked and scared of her and that is what led to him becoming subservient. The mistress had a great time with him and she enjoyed the process of changing him.
These mistresses did not like how their accountant tried to swindle them. The mistresses had trusted him but when they realized he was a swindler, they chose to teach him a lesson he would not forget and then look for another accountant who was professional and honest. The punishment they chose for him was to shit on him and they made sure he ate all their shit and drank their pee too.