http://ic.net/~erasmus/RAZ460.HTM
General
Whatever may be the position theologically that one may take today on the subject of Mariology, one is not able to call to one's aid 'reformed tradition' unless one does it with the greatest care . . . the Marian doctrine of the Reformers is consonant with the great tradition of the Church in all the essentials and with that of the Fathers of the first centuries in particular . . . . .
In regard to the Marian doctrine of the Reformers, we have already seen how unanimous they are in all that concerns Mary's holiness and perpetual virginity . . .
{Max Thurian (Protestant), Mary: Mother of all Christians, tr. Neville B. Cryer, NY: Herder & Herder, 1963 (orig. 1962), pp. 77, 197}
The title 'Ever Virgin' (aeiparthenos, semper virgo) arose early in Christianity . . . It was a stock phrase in the Middle Ages and continued to be used in Protestant confessional writings (Luther, Calvin, Zwingli, Andrewes; Book of Concord [1580], Schmalkaldic Articles [1537]).
{Raymond E. Brown et al, ed., Mary in the New Testament, Phil.: Fortress Press / NY: Paulist Press, 1978, p.65 (a joint Catholic-Protestant effort) }
Mary was formally separated from Protestant worship and prayer in the 16th century; in the 20th century the divorce is complete. Even the singing of the 'Magnificat' caused the Puritans to have scruples, and if they gave up the Apostles' Creed, it was not only because of the offensive adjective 'Catholic', but also because of the mention of the Virgin . . .
[But] Calvin, like Luther and Zwingli, taught the perpetual virginity of Mary. The early Reformers even applied, though with some reticence, the title Theotokos to Mary . . . Calvin called on his followers to venerate and praise her as the teacher who instructs them in her Son's commands.
{J.A. Ross MacKenzie (Protestant), in Stacpoole, Alberic, ed., Mary's Place in Christian Dialogue, Wilton, Conn.: Morehouse-Barlow, 1982, pp.35-6}
As I posted in #86...
"Neither the later Luther nor Calvin believed in Mary's bodily assumption into heaven nor in any immaculate conception concering Mary's own birth. Both held cursory opinions on the continued chastity of Mary which were discarded, for all intents and purpose, as they matured in the faith. Regardless, a belief in Mary's continued chastity after marriage does not require a mystical, supernatural act of God to support it, which is inherent in the fabricated, non-Scriptural beliefs that Mary rose into heaven bodily and that she herself was born without sin.
Keep your eye on Jesus Christ."
"While retaining a belief in perpetual virginity, Luther did so in undogmatic terms, making sure that Mary was not to be deified for such an attribute. He implied in the Table Talk that it was Mary’s choice to remain a virgin after the birth of Christ, rather than her continued virginity being a miraculous gift from God. However, Luther did not hold a lifelong belief in Mary’s immaculate conception. The Quote above from Luther’s "Sermon On the Day of the Conception of the Mother of God” was brought to cyber-space via Catholic historian Hartmann Grisar. A Catholic apologist quoted Luther from Grisar’s book and disregarded both the historical context of Luther’s writings, as well as Grisar’s explanation of the quote. If one looks up the reference, Grisar states, “The sermon was taken down in notes and published with Luther’s approval. The same statements concerning the Immaculate Conception still remain in a printed edition published in 1529, but in later editions which appeared during Luther’s lifetime they disappear.” The reason for their disappearance is that as Luther’s Christo-centric theology developed, aspects of Luther’s Mariology were abandoned. Grisar recognizes this. In regards to this Luther quote, Grisar says, “As Luther’s intellectual and ethical development progressed we cannot naturally expect the sublime picture of the pure Mother of God, the type of virginity, of the spirit of sacrifice and of sanctity to furnish any great attraction for him, and as a matter of fact such statements as the above are no longer met with in his later works.” In regard to Therese’s Calvin quote, it really isn’t certain that Calvin held to the perpetual virginity of Mary. A few quotes from Calvin have been used by Catholics to prove his adherence to it, yet a close reading of the quotes doesn’t really prove anything definitively. Calvin’s main point in his comment on Matthew 1:25 is that the gospel writer did not wish to record what happened afterwards to Mary. Calvin calls it “folly” at one point, when describing those who wish to make a text say more than it does. Those who would make a necessary inference where the Gospel writer has only made a possible inference engage in folly (according to Calvin). So it can’t really be concluded that Calvin is teaching here Mary’s perpetual virginity, it sounds to me as if Calvin is simply being careful. While I myself would make a possible inference from these passages that Mary had other children, It cannot be concluded that Calvin believed in Mary’s perpetual virginity, or her “sinlessness”, only that Calvin held the gospel writer does not explicitly say, one way or the other. Interestingly, this conclusion was reached similarly by William Bouwsma in his book, John Calvin: A 16th Century Portrait. He says in a footnote on p.275, "Among matters on which (Calvin) discouraged speculation were the order of angels and the perpetual virginity of Mary."