Novelist Sheri S. Tepper once had an elder sister protagonist who explained the difference between rape and sex to a younger brother who had been hanging around with sniggering teens propagating the "they all want it really" view. In it she pointed out that liking chocolate cake is not the same thing as liking to have chocolate cake shoved down your throat with a stick no matter how much you say no, or resist, or are in danger of choking and the cake just keeps on getting shoved down your mouth; and that it's made infinitely worse if people dismiss your complaints with "oh, but it can't have been that bad: you love chocolate cake!".
Let's not forget about those days when really, you just kind of don't want cake right now.
Originally posted at Xtinian Thoughts. Comment here or there.