Lady Bertie does not like anyone giving her the silent treatment. She is the only one allowed to give it to others. When her slave gave her the silent treatment, she was pissed and instead of finding out what the problem is, she punished him for it. She made him lick and swallow her spit. She spat on his face repeatedly and he had no choice but to lick it.
Mistress Amanda spat into her water and she used it to humiliate her slave. She knew it was a hot day and he definitely wanted water to quench his thirst. She spat into it before she gave it to him. But he did not see her spit into it. He was suspicious as he knew what kind of mistress she was. But she allayed his fears by pouring the water and he thought it was good water and nothing had been added to it.