If you're talking about the emotionally heavy, dramatic kind of incest narrative, you're probably looking beyond the surface-level shock value stuff. I've seen threads pop up on certain fanfiction sites where writers really dig into the family tension, the guilt, and the forbidden aspect, but it's often framed within a larger, angsty story. It's not the main selling point, more like a tragic backdrop for character destruction.
You might have better luck searching for tags like 'dark family drama' or 'taboo romance' on platforms like Archive of Our Own, but you gotta sift through a lot of unrelated works. Sometimes authors on Patreon or personal blogs explore these themes with more narrative weight, but they're understandably hidden behind layers of content warnings and paywalls. Honestly, half the search is navigating the murky waters of what different platforms allow.
I remember one story, can't recall the title now, that handled a sibling relationship as this slow-burning tragedy over years, with all the external societal pressure. It was less about the sex and more about the emotional wreckage left behind. Those are the ones that stick with you, but they're also the hardest to find without stumbling into just pure fetish material.