I first learned that Jesus had brothers and sisters in a bible study class taught at a Catholic church by a Catholic priest. To this day I am grateful that priest taught the Bible as it is written and did not make up things along the way.
The Bible does mention the fact that Mary was married to Joseph and that Jesus had brothers and sisters. Physical intimacy between a husband and a wife is a gift from God and there is no reason to believe this was denied to Mary and Joseph. The Bible mentions that Mary was a virgin at the time Jesus was conceived, but does not say she remained a virgin her entire life and that she did not consummate her marriage with Joseph. Nor does the Bible mention any of the circumstances surrounding Mary’s own birth or mention the possibility that she was conceived of an Immaculate Conception herself.
The notion that Mary and Joseph shared physical intimacy as husband and wife and that other children followed Jesus’s birth appears to be in accordance with everything written in the New Testament and does not take anything away from Joseph, Mary, or Jesus.
This topic is debated EVERY SINGLE DAY on FR, there's nothing I can add to it.
I was merely pointing out the inherent flaw in thinking that Mary and Joseph had a "normal" marriage.
There is nothing "normal" about having angels appear to tell someone that they will bear the Son of God.
Keep in mind that the "normal" reaction of someone in Joseph's situation would have been to have Mary stoned to death.
When an angel tells you to leave the country in the middle of the night and stay away until you are told to return and you recognize the unprecedented magnitude of what you've been tasked with, it would seem that everything else, including sex, would lose priority.
Additionally, there is NOTHING in Catholic teaching that says that Joseph didn't have children from a previous marriage.
NOWHERE in the Bible does it say anyone other than our Lord was born to Mary. Neither James nor Jude identify themselves as brothers of Jesus, though Jude DOES say he is the brother of James. It would make no sense to entrust Mary's care to John after the Crucifixion if she had other sons.