Lady Scarlet is a daring and adventurous girl. She loves to try all kinds of things and today she was venturing into scat. She was interested in seeing how much fun she could have with her shit. That is why she did not add anyone else into her plans. She wanted to find out for herself before she did it with or on someone else. It was a lot of fun for her.
Lady Scarlet did not want to ask her tenant to vacate. She just needed him to get his priorities in order. So she punished him for late rent payment. She did it by turning him into a scat slave and feeding him poop. He had to learn his lesson and he did after he was made a toilet slave. He did not want a repeat so he ensured that he paid rent on time.
Lady Scarlet had only set out to facesit on this loser and she did it. He assumed that she would only facesit on him and he endured it but he still talked shit to her and she had to punish him some more. That is what she did by turning him into a human toilet. He had no choice but to eat her poo as well as drink her urine.