"Charles II, himself a crypto-Catholic libertine, was reputedly appalled by James's folly in matters of religion and sex: 'My brother will lose his kingdom by his bigotry, and his soul for a lot of ugly trollops.'" John Mullan
Notice that he doesn't suggest that young women stop encouraging older men to chase them. And they do. It's not like women in their late teens and twenties couldn't find partners closer to their own age. Why is it the man's fault that that he might take advantage of such an opportunity? And why is it sexism?