I like reading and writing incest stories, specifically brother/sister incest.
My stories are mostly about how the siblings get to the part to have sex. The build up is the most important, and reluctance is of importance.
I don’t think any siblings just join joyfully in sex the first time they’re proposed.
Also, I write situational erotica. The story starts with a trigger and develops. Hopefully, I write some plausible scenarios.