You asked them about it? You just go up to strangers and ask them about their bedroom habits, and why they do what they do?
By the way, don't you think I'm a "diehard Catholic"? Doesn't my opinion (which is fact, BTW, not just opinion) count for anything?
Incidentally, I know just about all the "diehard Catholics" in a city of a million people. None of them have 16 children.
If you read my post again, these are people I KNOW.