I agree. This is my problem with the RCC - adding to Scripture. They've done it.
Now - BEFORE you say 'you are bearing false witness'......prove it.
Show me ONE verse from either the Old or New Testament (not 'traditions' or papal decrees) where God specifically states that the Mother of the Messiah will be (OT) or was born (NT) without sin. Then you have to show me a verse from the NT that specifically states that Mary remained a virgin AFTER the birth of our Lord.
If you can't do that I'm sorry my friend you've added to Scripture, and by your own words you're on a very dangerous road.
When did any of us claim those things were in Scripture?