Go to the Catechism:
[2522] Modesty protects the mystery of persons and their love. It encourages patience and moderation in loving relationships; it requires that the conditions for the definitive giving and commitment of man and woman to one another be fulfilled. Modesty is decency. It inspires one’s choice of clothing. It keeps silence or reserve where there is evident risk of unhealthy curiosity. It is discreet.
[2523] There is a modesty of the feelings as well as of the body. It protests, for example, against the voyeuristic explorations of the human body in certain advertisements, or against the solicitations of certain media that go too far in the exhibition of intimate things. Modesty inspires a way of life which makes it possible to resist the allurements of fashion and the pressures of prevailing ideologies.
2524 The forms taken by modesty vary from one culture to another. Everywhere, however, modesty exists as an intuition of the spiritual dignity proper to man. It is born with the awakening consciousness of being a subject. Teaching modesty to children and adolescents means awakening in them respect for the human person.
2533 Purity of heart requires the modesty which is patience, decency, and discretion. Modesty protects the intimate center of the person.