"That's good, slave. But do you really believe it?"
You are frightened that she doubts your sincerity. You redouble your efforts to worship her with your strokes and your words. You worshipfully stroke your cock as you gaze up at your goddess and say:
"Yes... yes, m-mistress! You... you *are* my g-goddess! You... you *are* all powerful! My cock *is* in your hand! Your... your perfect body *compels* my worship! My role in life is to... to *worship* you!"