[Frumanchu]

Thus, there are these two reasons why we don't find Christians talking about Mary's virginity the first 150 years. It was either already well known or it was not worth arguing about because it was already accepted.

Unnecessary exclusion. There is also the possibility that we don't find Christians talking about Mary's virginity (beyond the fact that she was a virgin when she gave birth to Christ) because she did not remain a virgin.

[P-Marlowe]

Unnecessary exclusion. There is also the possibility that we don't find Christians talking about Mary's virginity (beyond the fact that she was a virgin when she gave birth to Christ) because she did not remain a virgin.

The fact that Mary was MARRIED to Joseph is prima facie evidence of the fact that she did not remain a virgin. A marriage (by catholic tradition) is not official unless and until it is consummated.

Further the scripture clearly implies that her virginity was not perpetual;

And knew her not till she had brought forth her firstborn son: and he called his name JESUS. (Matthew 1:25 KJV)

So the chances are that there was no teaching on the perpetual virginity of Mary is simply because the scriptures state that she wasn't. It wasn't an issue because it wasn't an issue.

It think we can assume that Mary was always chaste. We cannot logically or scripturally assume that she was always a virgin.