My 13 year old son has always been obsessed with reading, and as he gets through so many books, a few years ago we bought him a kindle account. So we didn't have to approve every single book he read, we gave him an adult account a couple of years ago so he could choose and read to his heart's content.
We check the account sporadically and until 6 months ago there were no problems. However we found out that he had started to read some very explicit novels and we explained why these weren't appropriate and it was to stop, which he agreed. Recently I had another look and realised that the fantasy romance books he was reading that we thought were innocuous were actually 'why choose' and 'reverse harem', basically books where the woman has multiple sexual partners, very graphic and were advised for 18+ (I had to google what these terms meant as never heard of them!).
How should we deal with this? You don't hear much about written porn when it comes to teens! Obviously we'll have another talk about how these aren't appropriate for his age and that they don't represent healthy relationships, but I don't want to threaten to remove the kindle. He has ASD and reading has always been his passion and way to decompress and wind down. Is reading porn as damaging as watching it? Ironically we've never had problems with him accessing dodgy content on his phone.