In the further defining of the sanctity of Joseph and marriage let’s allow the words of J. Ivan Prcela to elaborate:

Saint Joseph was privileged to share in the Incarnation as the Virginal Father of Jesus by fulfilling the conditions necessary for that sublime mystery.  Besides being the God-preordained golden link of Jesus’ Davidic descendence, Joseph also fulfilled another necessary condition for the conception and the birth of the eternal, Messianic King.  According to St Jerome, St Augustine, St Bernard, St Albert the Great, St Thomas Aquinas, St Bonaventure and many other Catholic theologians, including John Paul the II the Great, St Joseph and the Blessed Virgin Mary had made a Vow of Virginity.  Mary was fully aware of that Vow when Gabriel announced to Her that God wants Her to become the Mother of His Eternal Son.  That is why Her question to the angel, ‘Quomodo fiet istud quia virum non cognosco—How this will be, for I don’t know man?’ expresses Her Betrothed Husband’s and Her own determination to live the Vow of Virginity even in Marriage.  Behind Mary’s humble and resolute virginal Fiat, there is also Joseph’s life’s permanent virginal Fiat, with which he made his and Mary’s Virginal Marriage possible.  This was God’s plan, foreseen, willed and decreed from all eternity. –J. Ivan Prcela ‘St Jospeh: The Virginal Father of Jesus’