^^Not a bad bluffer's job, there--I've taught Freud in college classes and that rings true.
Probably has something to do with the differences between how the male and female brains work.
And the differences between how men and women have--until recently--been socialized to deal with their sexuality. The rape fantasy has the benefit of absolving the woman from having to take any responsibility for her sexual feelings.
I am compelled to bring forth the example of Yeoman Barrows, who fantasizes about Don Juan -- who, upon his appearance, promptly attempts to ravish her, as was his wont. "I was just thinking, 'All a girl needs is Don Juan...'"