The Roman Catholic Church has ‘painted itself into a corner’ with regard to sex within marriage.
It is the definitive teaching of the Church.... The Church, nevertheless, in urging men to the observance of the precepts of the natural law, which it interprets by its constant doctrine, teaches that each and every marital act must of necessity retain its intrinsic relationship to the procreation of human life. (Humanae Vitae, n. 11)
From this we learn that sex within marriage is a sin unless the sole object is the procreation of Children. A ruling ‘interpreted’ from a supposed ‘natural law’ rather than clear commandments from God or Christ in the Scriptures.
According to the false doctrine of the Church, Mary had no children other than Jesus. One might reasonably suppose that this presents the Church with the problem that if Mary had normal sexual relations with Joseph after the birth of Jesus and produced, as the Church asserts, no children, Mary must have been rendered barren. Barrenness in a woman was a reproach among men; as testified by Elizabeth.
Luke 1:25 Thus hath the Lord dealt with me in the days wherein he looked on me, to take away my reproach among men.
As a less than perfect Mary is somewhat of a problem to the Catholic doctrine, the solution is perpetual virginity. It is of course unfounded nonsense. The Bible clearly indicates that Jesus had brothers and sisters.
Mark 6:3 Is not this the carpenter, the son of Mary, the brother of James, and Joses, and of Juda, and Simon? and are not his sisters here with us? And they were offended at him.
Galatians 1:19 But other of the apostles saw I none, save James the Lord’s brother.
The words used for sisters and brother are clearly used of siblings elsewhere.
Matthew 10:2 ...the twelve apostles are these; The first, Simon, who is called Peter, and Andrew his brother; James the son of Zebedee, and John his brother;
John 11:2 (It was that Mary which anointed the Lord with ointment... whose brother Lazarus was sick.) 3 Therefore his sisters sent unto him, saying, Lord, behold, he whom thou lovest is sick.
Joseph and Mary abstained from sexual relations until after the birth of Jesus.
Matthew 1:25 And knew her not till she had brought forth her firstborn son: and he called his name JESUS.
Jesus is called ‘her FIRSTBORN son’ rather than ‘her ONLY son’ or just ‘her son’ and this indicates that other children followed. Unconsummated marriage is grounds for annulment, making the marriage void.
There is ample information on the internet documenting the history of the rise of the blasphemous doctrines associated with Mary. Most of the teaching of the Catholic Church on ‘sins’ associated with sex within marriage is flawed and has no support in scripture. Note that the basis is the ‘natural law’, however that may be defined, ‘interpreted’ by the Church, rather than clear unambiguous statements from Scripture.
Hebrews 13:4 Marriage is honourable in all, and the bed undefiled...
Like the Jews before them the Roman Catholic Church exalts the ‘traditions of the fathers’ above scripture.
Mark 7:7 ...in vain do they worship me, teaching for doctrines the commandments of men.