58 The educators of the young clergy would render a more valuable and useful service, if they would inculcate in youthful minds the precepts of Christian modesty, which is so important for the preservation of perfect chastity and which is truly called the prudence of chastity. For modesty foresees threatening danger, forbids us to expose ourselves to risks, demands the avoidance of those occasions which the imprudent do not shun. It does not like impure or loose talk, it shrinks from the slightest immodesty, it carefully avoids suspect familiarity with persons of the other sex, since it brings the soul to show due reverence to the body, as being a member of Christ and the temple of the Holy Spirit. He who possesses the treasure of Christian modesty abominates every sin of impurity and instantly flees whenever he is tempted by its seductions.
Source: Sacra Virginitas (Vatican.va)