Meg and Ben share their son and his lover. It is filed under taboo incest, and runs about 4900 words. 4.4 out of 5 from 70 readers. Part 18 of On the Beach.

Turbidus also wrote False start.

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.