They come so close to being together, but alas... It is filed under taboo incest, and runs about 784 words. 4.0 out of 5 from 188 readers. Part 1 of One of These Days.

butterfly_lies also wrote I am War and Behind the Looking Glass.

Others under taboo incest Older Sister's Embrace, My Lingerie-Loving Sister Moves In and 2 Moms, 2 Sons... Ch. 5, and 9 more.

Or keep going.