One big load of unbiblical hogwash...
I do not know man"
That's not what Mary said...She said, Luk 1:34 Then said Mary unto the angel, How shall this be, seeing I know not a man?
Mary knew not a man, but her intention was to 'know' a man, and become his wife...And as the scriptures tell us, Mary eventually 'knew' Joseph...Believe God...
Actually, history tells us that when young Jewish girls took vows of chastity it was FOR LIFE. Much as it is today with nuns. What Mary was saying was that "How can this be --- because I know not man, (nor will I ever). You see, my friend, if Mary had intentions of breaking her vows one day and "knowing" a man, she would have had no need whatsoever to ask that question in the first place: "But how shall that be"? She'd have known perfectly well "how that would be".
And no, the Scripture do not tell us that Mary had other children. Some verses refer to "Jesus' brothers and sisters', meaning his followers, disciples and brothers and sisters in the spirit who followed his every word. The ENTIRE Bible is rife with the term "brothers", clearly referrng many times to like-minded followers, or close friends. But notice that the New Testament NEVER calls anyone "Mary's sons or daughters", NEVER. That's why the Protestant argument agaisnt the Virgin Mary's perpetual virginity crumbles like a moth's wing when you touch it.
Furthermore, in those days the Jews spoke Aramaic, and there was no term for "cousin", so a cousin would indeed be often referred to as "brother". In fact, even UNCLES were often referred to as "brother". Thems just the facts, my ignorant friend. I hope I've enlightened you a little.
Now, if you want to brawl against the Catholic Church, go do it someplace else. Please.