When you say culturally influenced belief, which culture are you referring to? Among Jews sex between husband and wife is normal and good and not having sex would be a cause for divorce.
Would it be right to say that this view that sex would "have desecrated her [Mary's] body" based on the view that sex is bad or dirty?
Also, why is Mary venerated and not Joseph? Under the view that Mary remained a virgin Joseph did too by default. They remained married from what we can conclude in the Bible.
Can you tell me if the belief that Mary is virgin, immaculate or "full of grace" are one and the same definitions and on virginity is it based on having a hymen in place or on not having had sex with a human man?
I am not looking to contend, just to understand your and the Church's (I assume Eastern and Western treat Mary the same) views on this issue. Thanks.
Just to be clear, immaculacy is not a word normaly used (it means "without stain"). You probably mean Immaculate Conception of Mary. That is the doctrine that Mary was conceived without originall sin. Sinlessness is a separate doctrine, that Mary never committed an actual or personal sin. Virginity is absence of carnal relations with a man. It is believed that God opened the Blessed Mother's hymen to allow for the birth of Jesus, and then he closed it, but that is not a dogma of the Church, just a common belief.
Fullness of Grace is a state incompatible with actual or personal sin. St. Stephen is described as full of grace at the time prior to his martyrdom, although the Greek word describing Mary is different and used uniquely in application to her. The fact that the Angel calls her already filled with grace as he meets her is sometimes used to give a biblical prooftext of her sinlessness as well as her immaculate conception. But we believe that fullness of grace is not something unique to Mary; it is a sanctified condition that pious people achieve with divine help.
The Catholic understanding is that a wife does not sin if she has normal, loving and non-contracepted carnal relations with her husband (and vice versa). On that score alone, Mary would not have sinned if she did the same either. Catholicism never viewed legitimate sex as "dirty". Perpetual virginity of Mary was fitting for her not because she avoided sin, but because she already fulfilled abundantly the union with God by carrying Him, raising Him, serving Him, and believing in Him, thanks to her unique role as the Mother of God.
Let us step back for a while and understand that spousal sex, to a Catholic Christian, is a model and a prefigurement of creative power of God and his love for us. Sex is pleasurable because it is a foretaste of Heaven. We are given spouses to love, and love carnally, so that we can understand and experience loving on the divine level, which through the Incarnation is carnal also. (I trust the good taste of the reader not to make silly caricatures of this). So for that reason sex for Mary would have been superfluous, akin to someone in the middle of a sumptuous dinner dashing off for a quick hamburger.
Joseph is venerated alongside Mary by the Church, as are all the saints, but his role in the Incarnation is secondary compared to Mary. It is Mary and not Joseph who gave Christ his humanity and it is Mary who accompanied Jesus through His minitry and witnessed the birth of the Christian Church at the Pentecost. (It is believed that Joseph was much older than Mary and died at some point before Jesus began his public ministry).
Lastly, what I outlined is Catholic theology. The popular belief through the ages was probably less precise. It is entirely possible that millions of Catholics held some jumbled "culturally influenced view" that a sexual act alone and regardless of context is tainted with sin and therefore incompatible with Mary.
The Jewish culture, of course, but also the early Christian culture as well, especially Pauline morality regarding virginity.
Among Jews sex between husband and wife is normal and good and not having sex would be a cause for divorce
Indeed, but not with what has been set aside for God. The idea that what is God's is untouchable is very much part of the Jewish culture (Holy of Holies, the Ark of Covenant, which when touched kills an Israeli soldier). Secondly, Mary's purpose was fulfilled; anything else would be second fiddle in the eyes of the Church. The mother of God cannot now be also the mother of fallen humans, spiritually or physically. Her purpose would otherwise be lost and made meaningless.
We don't think like the Jews and the early Christians did. We don't stone our misbehaving children, or cheating spouses to death. Yet in the ancient world, that was culturally acceptable and a part of the justice system. We can't apply modern social standards in 21st century America and say it's silly.
Jewish approach to holiness was also anything resembling ours. They couldn't even pronounce sacred names. Earliest Christian manuscripts never spell out God or Christ or other sacred names but always use ligatures. The reverence of the ancients cannot even be fathomed by modern-day Christians.
Naturally, Mariology evolved along with the rest of the Church beliefs, and in order for that to take place a cultural environment that made it possible had to exist. Obviously, it would not have happened in the 21st century America. But in those days such a culture did exist, no one objected to it.