She wanted him to take her? No-one had ever told him that before. This put pressure on him, this worried him; the woman had always been in control during these sorts of things, especially Daphne, but in her state she would probably not want to be the dominant one, here. His feelings were all conflicting him and he became breathless not simply because she was alluring him.
"I... Daphne, I'm not.." he began, wanting to say 'experienced enough' but fearing the outcome.