Every line of his body speaks of interest in her and what she's doing, and Clark forces down the nervousness. His heat vision is well under control, his hands restrained in his own iron grip and held out of harm's way. He lets her set the pace, since this is her show today. He likes letting her call the shots, let him know what she's comfortable with, not forcing her or pressuring her into doing anything she doesn't want to do. He never wants to be one of Those Guys. So he just listens, and watches, and enjoys the feelings she elicits from her movements.