Hi, I'm looking for those kind of stories in which the protagonist happens to watch a (close) relative having sex. Whether an intimate relationship between those two develops isn't that important but I'd really love to have detailed (and maybe conflicting) thoughts shown by the watcher.
I've already read quite a bunch of these stories and am certain there are a lot still to discover. Hope you know more with this theme or could recommend authors who specialize in this recently developed fetish of mine.