A slash fanfiction involving twins in a romantic and/or sexual relationship. Many fans find this an abomination.
Some Noteworthy Categories of Twincest Fanfiction:
Fred and George from Harry Potter.
Rin and Yukio from Blue Exorcist.
Fred and George from Harry Potter.
Rin and Yukio from Blue Exorcist.
by SilawenGreenleaf June 27, 2011
by BobbySmallGland November 18, 2018