Madame Marissa did not appreciate how rude her slave was and she had to nip it in the bud. She is not one of those mistresses who chase away a slave at the slightest provocation. She prefers to mold them into what she wants. For this slave, her preferred method was to spit on him and degrade him. That way, she cut his ego. She had him swallow her spit before using him as her human ashtray.