It isn’t reasonable to assume, as God was the Father of Jesus, not Joseph. Joseph was to protect both Mary and Jesus, but her body was reserved as a tabernacle for Jesus.
Joseph knew she was chosen by God, set apart. In setting her apart, she would have been physically reserved, so to speak.
Her perpetual virginity is a foil to Eve, as was her “Yes,” to God. Mary played a role in the reversal of man’s condemnation. Hers was to be both an example of obedience, but also provide humanity to Jesus. It was to suffer, as she was foretold by Simeon. It was also to nourish Jesus.
Eve on the other hand, disobeyed God. She helped to bring sin into the world. In the Garden, she suffered nothing. She most certainly didn’t nourish Adam by giving him the fruit of the tree of the knowledge of good and evil. She carried original sin.
Mary carried the light of the world!
Here is a good article that will do a better job than I can explaining. http://www.catholic.com/tracts/mary-ever-virgin
What you are presenting here is strictly theory and conjecture. Not an OUNCE of fact is presented here. The Bible mentions that Mary was a virgin ONLY at the time of her conception of Jesus. Period. It ends there. Since Mary and Joseph were a MARRIED COUPLE and since the Bible mentions Jesus’s brothers and sisters, it is reasonable, natural, and normal to reasonably conclude that Mary and Joseph had a happy normal close marriage which was blessed with other children. Why is this soooooooooooooooooooooooooooooooooooooo difficult to believe????? To believe otherwise, you would have to conclude that Joseph was a passive wall flower and that Mary and Joseph slept in separate rooms. I don’t think that’s how Holy Matrimony works for anyone. You just offer theory not facts based on Biblical accounts which is our primary source.
God’s plan is for Holy Matrimony. His plan is for to be fruitful and multiply. He created Eve because He did not want Adam to be alone. The Church invented celibacy. That is NOT God’s plan for Mary and Joseph. That is NOT God’s plan for men and women. That is SPECIFICALLY NOT God’s plan for the clergy-—for proof of this simply read 1 Timothy 3:1-7. READ IT AGAIN. Then you tell me what that means. Holy Matrimony is God’s plan for men and women and their families. This all throughout the Bible. Only the Romans seemed to glorify virginity as goal in of itself-—remember the vestal virgins? Of course celibacy is the preferred state outside of Holy Matrimony. But marriage is God’s plan for us-—and this not to be excluded to our clergy if you read 1 Timothy 3:2.