Bitch is definitely a swear word in American English.
The issue is that they're probably not looking at naked ladies. They're probably watching hardcore anal and gang bangs and learning that this is "normal" sex.
That's nothing new. Have you seen any of the Carry On... films?
Oooh, matron!
You couldn't use it (well I wouldn't) to any female, unless I knew of them not getting offended (relaxed sense of humour, good friend etc.) or I really wanted to upset someone.
It is not a word to be used lightly in North America.
On a side note, when watching the Westminster Kennel Club Dog Show, my immature side is out of control from the casual use of the word bitch---albeit, in a more proper, etymological sense.
Back on topic, here's an interesting response from a father who noticed some 'personal' sites on his son's browser history. (xpost from reddit)
As they do kids versions of most things these days, maybe they should do something, oh what would be a good marketing term ... "kiddie porn" for kids. I'm sure that would go down well.
It's not?
Fair point, but whatever the content my main point is that there is relatively little parents can do to stop an adolescent boy looking at porn, even more so in the world of smartphones. It's out there and it will be discovered and shared as it always has been in my view.
I'm not saying this isn't something to be concerned about, especially as the content is getting ever more explicit and access to it ever easier. I just don't think teenage boys have changed much in this respect over the last couple of generations and will always be one step ahead of their parents (until they get caught )
I'm still trying to work out what a " prevert" is. Maybe a cross between an advert and a pervert!