The Witcher series has spawned a lot of fanfiction, but that's not entirely surprising. It's a fantasy series starring a bunch of hot characters - many of which get it on, or can get it on in the games. At the time of writing, there are 46,016 fics on the site Archive of Our Own - 11,567 of which are labelled as "explicit". Turns out, the cast is very aware of this.