Brother sister sex Stories with lots of romance
Special emphasis on love between them.
https://storiesonline.net/universe/712/brother-sister-love
https://storiesonline.net/a/Richard_King
https://storiesonline.net/s/41821/sister-time-travel
https://storiesonline.net/a/Angel
https://storiesonline.net/series/1317/the-adventures-of-art-trange
https://storiesonline.net/a/aroslav
Premier only:
https://storiesonline.net/s/37468/always-loved-her
https://storiesonline.net/a/General_Principle
https://storiesonline.net/a/Lubrican
Lots of brother-sister, some with good story development and character growth, others, well, if he says it's a stroke story, believe him. 256 stories, currently, and he's still posting. Also lots with "Uncle Bob"; it's never the _same_ Uncle Bob; uncle-niece stories, again some with very good development, others, not. Other more general incest. Pregnancy is a common result. Also some general erotica. One thing is for sure, there _will_ be sex, but it won't be _purely_ gratuitus.
https://storiesonline.net/s/65149/dont-ask-dont-tell My all time favorite Robert Lubrican brother-sister story. Premier. Or you can get it for a few dollars at Barnes & Noble or Amazon. Most of his work is available at those two retailers.
But if you can afford a premier membership, you'll be supporting the site, and able to download _all_ SOL stories in various formats, not just those which the authors are marketing elsewhere. Which will make them available to you when you are in a care facility with just an eReader or Tablet, and no Internet access; that's part of why I went Premier, I'm planning ahead, preparing for the day when I need more assistance than family can provide, especially since I'm the youngest.
And if you've downloaded them, you'll still have them if the author chooses to remove them from the site. Lost a couple of good ones that way, not going to happen to me again.