Maybe these will help.
[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}
Martin Luther
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) }
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) }
John Calvin
[On Matt 1:25:] The inference he [Helvidius] drew from it was, that Mary remained a virgin no longer than till her first birth, and that afterwards she had other children by her husband . . . No just and well-grounded inference can be drawn from these words . . . as to what took place after the birth of Christ. He is called ‘first-born’; but it is for the sole purpose of informing us that he was born of a virgin . . . What took place afterwards the historian does not inform us . . . No man will obstinately keep up the argument, except from an extreme fondness for disputation. {Harmony of Matthew, Mark & Luke, sec. 39 (Geneva, 1562), vol. 1, tr. William Pringle, Grand Rapids, MI: Eerdmans, 1949, p.107}
Huldreich Zwingli
I have never thought, still less taught, or declared publicly, anything concerning the subject of the ever Virgin Mary, Mother of our salvation, which could be considered dishonourable, impious, unworthy or evil . . . I believe with all my heart according to the word of holy gospel that this pure virgin bore for us the Son of God and that she remained, in the birth and after it, a pure and unsullied virgin, for eternity. {Max Thurian (Protestant), Mary: Mother of all Christians, tr. Neville B. Cryer, NY: Herder & Herder, 1963 (orig. 1962), pp. 76}