Mistress Mystique is a generous girl but this guy abused it and she was not going to let it slide. She had to punish him and she did it cruelly by turning him into a human toilet. He was shocked by what she did to him and that is how he changed. In addition to peeing on him, she spat into his mouth and she even made him lick her pussy and asshole.
This guy was a loser and mistress Mystique knew that she was not going to do anything with him. But he lied to himself that she would and he went ahead to try to get him to sleep with her. She did not and in fact, she humiliated him for even trying to. The mistress turned him into a human toilet and she forced him to drink her urine. He did.