It's not about pornography, it's about respecting other people.
Little Wing has already revealed to us that she understands the issue here, but her failure in parenting is that she sided with her child over siding with the right thing to do.
As a parent, you lead by example. Telling your child that they are wrong and made a mistake is something that HAS TO HAPPEN, if it doesn't, you end up with a generation of self-serving brats who have no idea how to conduct themselves in a society that doesn't revolve around themselves.
In life, there's always times when you make the bad decision or say the wrong thing. The big thing that separates adults from children or idiots, is the ability to see the error in your ways and correct it, not fight it to the death.