Catechism of the Catholic Church §2522 — excerpt
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.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.