In a sense, he is mimicking what she is doing to him, her responses to his touches work to inspire his next actions, the movements of his lips and tongue against her cunt. It is a way for her guide him, tell him what she finds most pleasurable, tell him what she desires him to do to her.

And when she rocks her body against him, he responds in kind by running his fingertips over the bare skin of her legs, tracing patterns on her calf muscles, letting his nails lightly graze her thighs. Any way that he can add stimulation, add pleasure, he is going to do it. Lips, tongue, fingers, voice - all of it.