I also hate having filthy language and visuals paraded across the TV screen when my daughter or son is present. I was particularly offended once in Amsterdam, when, in a checkout line, I was subjected to close-up photos of fellatio on magazine covers in the presence of my teenage son.
On the other hand, I am an adult, and if I choose to watch skin-flicks, it's nobody's business but my own. And as to whether or not it is harmful to me--I'm the best judge of that.
Like alcholics and drug users, those addicted to porn rarely realize the harm it's causing them until such harm becomes substantial.