Replies

“However after Jesus was born it is ridiculous to believe that Joseph wouldn’t want to have sex (and other Children) with his wife,...”

Why? Most of Christendom throughout history has believed exactly that. Why should the very recent counter belief of a few heretical cults mean anything?

Christ, our Savior, was the real and natural fruit of Mary’s virginal womb . . . This was without the cooperation of a man, and she remained a virgin after that.
{Luther’s Works, eds. Jaroslav Pelikan (vols. 1-30) & Helmut T. Lehmann (vols. 31-55), St. Louis: Concordia Pub. House (vols. 1-30); Philadelphia: Fortress Press (vols. 31-55), 1955, v.22:23 / Sermons on John, chaps. 1-4 (1539) }
Christ . . . was the only Son of Mary, and the Virgin Mary bore no children besides Him . . . I am inclined to agree with those who declare that ‘brothers’ really mean ‘cousins’ here, for Holy Writ and the Jews always call cousins brothers.
{Pelikan, ibid., v.22:214-15 / Sermons on John, chaps. 1-4 (1539) }
A new lie about me is being circulated. I am supposed to have preached and written that Mary, the mother of God, was not a virgin either before or after the birth of Christ . . .
{Pelikan, ibid.,v.45:199 / That Jesus Christ was Born a Jew (1523) }
Scripture does not say or indicate that she later lost her virginity . . .
When Matthew [1:25] says that Joseph did not know Mary carnally until she had brought forth her son, it does not follow that he knew her subsequently; on the contrary, it means that he never did know her . . . This babble . . . is without justification . . . he has neither noticed nor paid any attention to either Scripture or the common idiom.

{Pelikan, ibid.,v.45:206,212-3 / That Jesus Christ was Born a Jew (1523) }
Editor Jaroslav Pelikan (Lutheran) adds:

Luther . . . does not even consider the possibility that Mary might have had other children than Jesus. This is consistent with his lifelong acceptance of the idea of the perpetual virginity of Mary.
{Pelikan, ibid.,v.22:214-5}