Except this is the last line of consent before the actual work. So if you’re at this button you have already done the following:
1) chosen to go onto AO3 in the first place
2) chosen the fandom you wish to read about
3) had the chance to filter for the things you do want to see like a specific pairing or a specific AU
4) had the chance to specifically filter out any tags you don’t want to see like, oh I don’t know, incest and non-con and dub-con and paedophilia
5) had the chance to set the rating level if you wish to remove any explicit content at all
6) have read the summary of the story, which aren’t always great but are the only indicator of what the story will be like writing wise so something about it was good enough for you to click on it.
7) have read the tags of the story which will tell you what is actually in the story. If you have used filters to remove stories with things you don’t want then there shouldn’t be anything in here that’s a shock to you but maybe there is. That’s why the tags are there for you to check for yourself.
8) Then you have to actually click on the story. You cannot see anything other than the summary or the tags without personally deciding that you are going to open and read this story.
9) Only here, at step number nine, do you get to the adult content warning pictured above. You have been through eight different steps, the last six of which have also been opportunities for you to see that this has adult content. And AO3 has *STILL* stopped you to ask one last time “are you sure you want to read this because it has things that only adults should see in it”.
If after this point you are reading incest and paedophilia then it’s probably because you specifically went looking for it.