As parents at bilang nasa dominantly Catholic country tayo, what's your take on sex before marriage? Do you think it's still a sacred thing or is it now passe?

It depends on your personal belief/faith. If we are to based it on the Bible, sex should only be done by husband and wife. Given that the Bible's passages/verses don't have expiration (what's written during the apostles' time is still applicable to us), then sex is still considered a sacred thing and must not be done by unmarried couples.