Saint Joseph protected the Blessed Virgin Mary and her most Holy Son, the Lord Jesus Christ. Why does this seem incredible to you? Surely you have read the word
undefiled in the holy scriptures?
[Psalms 119:1] Blessed are the undefiled in the way, who walk in the law of the LORD.
[Song of Solomon 5:2] I sleep, but my heart waketh: it is the voice of my beloved that knocketh, saying, Open to me, my sister, my love, my dove, my undefiled: for my head is filled with dew, and my locks with the drops of the night.
[Song of Solomon 6:9] My dove, my undefiled is but one; she is the only one of her mother, she is the choice one of her that bare her. The daughters saw her, and blessed her; yea, the queens and the concubines, and they praised her.
[Hebrews 7:26] For such an high priest became us, who is holy, harmless, undefiled, separate from sinners, and made higher than the heavens;
[Hebrews 13:4] Marriage is honourable in all, and the bed undefiled: but whoremongers and adulterers God will judge.
[James 1:27] Pure religion and undefiled before God and the Father is this, To visit the fatherless and widows in their affliction, and to keep himself unspotted from the world.
[1 Peter 1:4] To an inheritance incorruptible, and undefiled, and that fadeth not away, reserved in heaven for you,
[Wisdom 3:13] Their offspring is cursed. Wherefore blessed is the barren that is undefiled, which hath not known the sinful bed: she shall have fruit in the visitation of souls.
[Wisdom 4:2] When it is present, men take example at it; and when it is gone, they desire it: it weareth a crown, and triumpheth for ever, having gotten the victory, striving for undefiled rewards.
[Wisdom 7:22] For wisdom, which is the worker of all things, taught me: for in her is an understanding spirit holy, one only, manifold, subtil, lively, clear, undefiled, plain, not subject to hurt, loving the thing that is good quick, which cannot be letted, ready to do good,
[Wisdom 8:20] Yea rather, being good, I came into a body undefiled.
[Wisdom 14:24] They kept neither lives nor marriages any longer undefiled: but either one slew another traiterously, or grieved him by adultery.
[2 Maccabees 7:40] So this man died undefiled, and put his whole trust in the Lord.
[2 Maccabees 14:36] Therefore now, O holy Lord of all holiness, keep this house ever undefiled, which lately was cleansed, and stop every unrighteous mouth.
[2 Maccabees 15:34] So every man praised toward the heaven the glorious Lord, saying, Blessed be he that hath kept his own place undefiled.
The verses shown above are examples taken from the KJV. The use of the word "undefiled" does not imply that lawful marital relations are wicked. Even a lawfully married woman was accounted "unclean" at various times and also following the birth of a child.
[Leviticus 12:2] Speak unto the children of Israel, saying, If a woman have conceived seed, and born a man child: then she shall be unclean seven days; according to the days of the separation for her infirmity shall she be unclean.
[Leviticus 15:18] The woman also with whom man shall lie with seed of copulation, they shall both bathe themselves in water, and be unclean until the even.
[Leviticus 15:19] And if a woman have an issue, and her issue in her flesh be blood, she shall be put apart seven days: and whosoever toucheth her shall be unclean until the even.
[Leviticus 15:25] And if a woman have an issue of her blood many days out of the time of her separation, or if it run beyond the time of her separation; all the days of the issue of her uncleanness shall be as the days of her separation: she shall be unclean.
[Leviticus 15:33] And of her that is sick of her flowers, and of him that hath an issue, of the man, and of the woman, and of him that lieth with her that is unclean.
[Mark 7:25] For a certain woman, whose young daughter had an unclean spirit, heard of him, and came and fell at his feet:
The above verses are also from the KJV.
In the holy scriptures virginity is a state of purity. It may be physical and moral in nature. The ancient churches proclaim Blessed Mary as ever virgin primarily to emphasise her purity in life and morals the idea of chaste life within her marriage to saint Joseph is secondary even though it is important. If prurient curiosity drives some to assume otherwise then let them explain their prurience. For the faithful this matter was settled in the early centuries of the Church's history.