Lady Luciana now reduces the slave's precious air by pressing her hands firmly over his mouth and nose. His head is firmly clamped between her legs so that he can't turn away. That's just the way it is when he puts himself in her hands. Then he has nothing more to say and gets the oxygen squeezed our of him. He learns to let himself surrender to Lady Luciana. She has complete control over his breath. His will has no value here!