There is nothing in the Bible that says that Mary is (was) a "perpetual virgin". She was a teenager chosen by God to give birth to Jesus, followed by his brothers (and sisters?). Since it's not stated anywhere in the Bible that Jesus' siblings were the result of more births without intercourse, it's obvious that she was a virgin for Jesus' pregnancy only.<snip>
“We must therefore simply assert that the Mother of God, as she was a virgin in conceiving Him and a virgin in giving Him birth, did she remain a virgin ever afterwards."
The blessed Mary mother of God, is a perpetual virgin to the glory of God!