People undeterred by the catholic church's prohibition on sex outside marriage are unlikely to be reluctant to wear condoms because of doctrinal concerns, I'd have thought.
Having been an Evangelical Christian and 'assistant teen pastor' in a previous life, I've seen this in action in many different areas of life. People constantly did things they believed were wrong, and the combination of not being prepared or informed about those things and feeling ashamed about it afterwards led to a lot of suffering.