This mistress wanted her slave to lick her spit. She wanted to try it and she did not want to do it as humiliation or punishment. She was just curious. But he refused and she was pissed off that he had disobeyed her. He did not even do it politely. He did it rudely and she was pissed. She used her high heels to make him open his mouth and she now humiliated him with her spit.