Mr. Cunningham, I believe you are mistaken.
No, he isn't.
499 The deepening of faith in the virginal motherhood led the Church to confess Mary's real and perpetual virginity even in the act of giving birth to the Son of God made man. In fact, Christ's birth "did not diminish his mother's virginal integrity but sanctified it." And so the liturgy of the Church celebrates Mary as Aeiparthenos, the "Ever-virgin"."
Mr. Cunningham knows his stuff.
See
http://www.newadvent.org/cathen/15448a.htm
Here's two more examples in addition to the ones I've already posted about Luther.
"There have been certain folk who have wished to suggest from this passage [Matthew 1:25] that the Virgin Mary had other children than the Son of God, and that Joseph had then dwelt with her later; but what folly this is! For the gospel writer did not wish to record what happened afterwards; he simply wished to make clear Joseph's obedience and to show that Joseph had been well and truly assured that it was God who had sent His angel to Mary. He had therefore never dwelt with her nor had he shared her company.... And besides this Our Lord Jesus Christ is called the first-born. This is not because there was a second or a third, but because the gospel writer is paying regard to the precedence. Scripture speaks thus of naming the first-born whether or not there was any question of the second." John Calvin, Sermon on Matthew 1:22-25, 1562
"I firmly believe that Mary, according to the words of the gospel, as a pure Virgin brought forth for us the Son of God and in childbirth and after childbirth forever remaaned a pure, intact Virgin." Ulrich Zwingli, Zwingli Opera, Vol. 1, pg 424.