trt - don't know where you get your ideas from, but 30 years ago it was shameful if a 14 year old girl was having sex, regardless who with.
Yes, it did happen, and yes, there were pregnancies, but it was never acceptable.
A man in his 30s having sex with a 14 year old girl would certainly be frowned upon.
You can see from this graph there were far more convictions for underage sex in the 70s than now - many more.
http://www.famyouth.org.uk/bulletin.php?number =117