I remember reading a story several years ago about a family with a long-standing tradition of incest. I can’t seem to find it again. Incest Family Tradition isn’t necessarily the title. I don’t remember the title.
I believe the family was wealthy/prominent in their community, with of course their dirty secret that no one suspected. The backstory was that the men in the family (going back generations) all had insatiable sexual appetites, and the tradition was put in place to keep the men from straying (or along those lines).
The men were initiated on adulthood, and would have sex with all the women in both their immediate & extended families. The main character was initiated with a gangbang of his aunt with his cousins, with a teaser at the end that his own mom was next.
Pretty sure it was first-person from the main character’s POV.