it's funny, i find that when a girl really likes me, she is less willing to give it up on the first date cause she doesn't want me to have "that" image of her. whereas ive had experiences with really hot chicks, who could easily get a boyfriend if they wanted, that are down on the first night cause they don't care what you think about them, cause they don't really care about you. keep in mind there are a ton of factors that have nothing to with you, which play into women's decision making. if you were just looking for a one night thing with this chick that is kind of a bummer, but it's not worth blaming yourself over.