In some settings, it is taken as a given not only that All Men Are Perverts who think about sex constantly, but that the average man will immediately attempt to force himself upon any woman who isn't sufficiently protected. Simply not raping a woman is therefore in itself a sign that a man is a pure and noble hero.
Particularly common in Low Fantasy settings whose writers are trying too hard to avert Politically Correct History or Anvilicious Straw Feminist works. Also often goes hand-in-hand with a Sweet Polly Oliver heroine, as this is the only way a woman can leave her home in one of these stories without being set upon. Strangely, men are rarely seen as targets for this rampaging rape culture, except in prison movies where it's likely to be used as comic relief.
Also shows up in old-fashioned romance novels, perhaps as an attempt to demonstrate the desirability of the heroine. In some of these, the only one who will succeed in raping the heroine will be the hero!