Teens are still going to have sex, regardless of how much society attempts to stamp out all discussion of it. Usually stifling discussion of sex just makes "accidents" much more likely, both because they are uneducated about it, but it also seems more cool and something to rebel against your parents with. Many Nordic cultures are very open to nudity and sex, and I don't see Sweden and Norway descending into chaos and babies in the streets.
Anyway, in this particular case Papers, Please is about as far from making sex "cool" as possible. You play a border immigration agent for a dystopian, totalitarian state in the vein of old Soviet bloc countries. The whole purpose of scanners to check people for contraband mirrors the same discussion we've had about the TSA's scanners in airports. It's supposed to make you feel like you're intruding upon others' privacy. It's definitely not suppose to be arousing.