worts..." (The Merman's Children, Book Four, Chapter II, p. 200)
Poul Anderson sets the scene before recounting an incident between Tauno and Eyjan. I said here that the issue of incest arises at least three times in Anderson's fantasies. (See also here.) There is a fourth, in The Merman's Children.
Merpeople have no incest taboo. However, Tauno and Eyjan, brother and sister, are merfolk-human hybrids whose Christian mother did impress this taboo on them. However, alone together for a long stretch, they overcome the taboo and attempt sex. However, the taboo is stronger than them and they can't do it. Is there any right or wrong here? I have a strong distaste for the idea of brother-sister incest but that is not a moral judgment.