Orgasm is a sporadic response that arises when the brain responds to stimuli of an erotic nature. Due to this mental arousal the brain sends blood to the phallus (causing tumescence) which makes orgasm possible. No one (not even a man) can orgasm from stimulation that is not synchronised with their own state of arousal. So intercourse will never cause orgasm for the receiver. No arousal means no orgasm. So the fact that no one can name any female erotic turn-ons with a lover is significant.