It wasn't hard to continue showing him as she tried her best to practically swallow him whole. Her eagerness was shown as she rocked her hips and moved her mouth. It was so easy to lose herself to this lust when her pleasure rose. Why be nervous when all he wanted to do was make her come?
And she wanted to make him come as well. So when he tugged her hair, she moved how he wanted her to, giving him complete control of her and finding that she liked it.