Excellent discussion here.
Accountability is a key in my opinion.
James 1: 14 - 15 states, “But each one is tempted when he is drawn away by his own desires and enticed. Then, when desire has conceived, it gives birth to sin; and sin, when it is full-grown, brings forth death.” I believe that our “own desires” change as we get older. New types of sins are introduced to our body, soul (mind, will and emotion) and spirit.
It is true that some sins may be introduced early on so that we "desire" before we should. However, sooner or later, as we grow and develop many of those temptations will come our way with or without exposure.
The desire for sexual stimulation does not appear to be lessoned in countries where family nudity is more acceptable. So there does not seem to be a "fulfillment" of those desires. However, teaching children about God's desires for sexual union is very, very important!
So, as we "conceive" sin, how then can we overcome this temptation? I agree that God's grace - a power to overcome, is a major part of the ability to overcome. Another huge help is accountability (discipleship). We have computer filters. When my son lived with us (now a graduate and on his own) I gave him the password to the filter so he could override it if he wanted to, but he knew I would see the report telling me everywhere he went. This accountability was a great help.
I have written a short booklet for parents on setting limits. It has a chapter on the
James 1 and its implications to our children. (Send an email to bookrequest-at-colossians2.com for instructions on how to download the book for free.)
One thing is for sure. We need to be in prayer for our children!