Had you drunk anything? Its definately a problem as next time you'll be more nervous. But remember, she wont think less of you, if anything it'll make her more insecure as she couldnt get you a hadron, like imagine if you couldnt get a girl wet, you'd blame yourself before you blame her unless your really experienced. It's all cool man, next time do shit to her to turn yourself on and all will be good, just dont worry, its not a big deal unless you make it one.