The Catholic presumption that Mary took a perpetual vow of virginity as a young girl presumes she knew enough about sex at an age she should not have, presumes that she knew the future and knew she would bear the Messiah, more than implies that she entered a marriage contract with Joseph under fraudlent terms, with no intention of fulfilling her role as a married woman, and leaves Mary and joseph living together under false pretenses, pretending to live as a husband and wife before the world when they weren’t, making them party to deception and perpetuating it.
Their whole position on trying to rationalize the Mary and Joseph situation is rife with illogic.
Rome 'presumes' an awful lot of things that are NOT found in the bible.
This is why I do NOT follow all of it's teachings.
When a religion is hallmarked by magic thinking, any imagination can be made dogma.