I see a major barrier in our movement being that society perceives children to be "innocent" and therefore must be shielded from "impure" acts such as sex.

They might also see sex as an added complication in their children's lives, not necessarily damaging either. They have many worries in trying to keep their children safe and if they perceive an additional, and perhaps unwarranted, further complication then that might be enough reason for their supposed protective stance. Perhaps they also know that most children are not exactly 'innocent' 100% of the time or in all areas.

Moth