Not under 18 years old

Hi! Greetings.
I`m not sure if exists a solution to my issue.
I have a site that fights agains aids. Obviously I talk about SEX and other IST. I have some pictures that are hard to see, as images of HPV effects in humans being. ANd other (I ask all night to God have mercy of these persons). I had troubles with google that named my content of sordid and violent. I lost my ad sense revenue but I did not care, because what I reaaly want is to prevent this issues. No google ripped me out from the first page. I was the firs result to some queryes for 14 years. What will be the next google step? I dont know, but I think that a good solution is give a warn page to under age limits. But Id like to have one of this that keep the route of visitor and after the ok of user he reaches the targeted page that he clickd in the search engine and not to redirect him to home page.

Do you, who read me now, know some plugin that does this or am I just imagining things that cannot happen?

Anyway, thank for your attention
Best regards
Claudio