Hermione blinked in surprise as she realised something ... this action worked for her. Harry still wasn't sure if he was supposed to fuck Hermione anally or not, worried that movement might hurt her, and perhaps it was better to stay still and just let Hermione clamp and unclamp around him as she had been doing earlier. She would just have to take control for now and get back to reassuring him later, when she had remembered how to speak in a respectful manner.