Bible says she was a good wife to Joseph in all ways. To me that means having sex with him. Many protestants believe that James was also her son—Father was Joseph this time. There were more as well. I have no problem with Mary being a good wife and mother—She is idealized for this. The Catholics must create the Perpetual Virginity myth to keep her as a demi goddess—to attract Romans and Greeks with a fertility symbol/Woman. They seem to forget the important thing is the Message of Jesus! The wonders are not the main point—they are just confirmations of his message and divinity.
It’s not limited to the Catholic Church—it is a belief among the Eastern Orthodox and other eastern Christian churches, and was held by many of the early Church Fathers (although not by all) and by some of the Protestant Reformers such as Luther and Zwingli. See the Wikipedia article on “Perpetual virginity of Mary” for numerous examples.
Matthew 1:20-25 20 But as he considered these things, behold, an angel of the Lord appeared to him in a dream, saying, Joseph, son of David, do not fear to take Mary as your wife, for that which is conceived in her is from the Holy Spirit. 21 She will bear a son, and you shall call his name Jesus, for he will save his people from their sins. 22 All this took place to fulfill what the Lord had spoken by the prophet:
23 Behold, the virgin shall conceive and bear a son, and they shall call his name Immanuel
(which means, God with us). 24 When Joseph woke from sleep, he did as the angel of the Lord commanded him: he took his wife, 25 but knew her not until she had given birth to a son. And he called his name Jesus.
Doesn't get more explicit than that. Joseph had sex with Mary AFTER Jesus' birth, just like any normal married couple.
Matthew 12:46-50 46 While he was still speaking to the people, behold, his mother and his brothers stood outside, asking to speak to him. 48 But he replied to the man who told him, Who is my mother, and who are my brothers? 49 And stretching out his hand toward his disciples, he said, Here are my mother and my brothers! 50 For whoever does the will of my Father in heaven is my brother and sister and mother.
Matthew 13:55-58 55 Is not this the carpenter's son? Is not his mother called Mary? And are not his brothers James and Joseph and Simon and Judas? 56 And are not all his sisters with us? Where then did this man get all these things? 57 And they took offense at him. But Jesus said to them, A prophet is not without honor except in his hometown and in his own household. 58 And he did not do many mighty works there, because of their unbelief.
Mark 6:3 Is not this the carpenter, the son of Mary and brother of James and Joses and Judas and Simon? And are not his sisters here with us? And they took offense at him.
Galatians 1:19 But I saw none of the other apostles except James the Lord's brother.
The Protoevangelium of James (c. A.D. 120) states that Joseph was a widower who already had a family and thus was willing to become the guardian of a dedicated or consecrated virgin. His children would have been step brothers and sisters of Jesus.
Peace be with you
Did not Isiah prophecy about a VIRGIN given birth to the Messiah?