there is this pretty nice arty book called „Please yoursELF-Sex with the Icelandic Invisibles“ by Hallgerður Hallgrímsdóttir about having sex with „huldufólk” aka elves. the book is hard to find though …
“ Surveys have shown that ten percent of Icelanders believe in the existence of “huldufólk” (the hidden people), dwarfs, spirits and other supernatural beings. Ten percent deny it, but the remaining eighty still refuse to rule out their existence.
Natives to Iceland, elves are very limber, light and strong which makes them excellent sexual partners. Unlike humans, elves have the ability to open up other worlds of sexual encounters. Although Hallgerður does not think they possess supernatural powers, she is sure that having sex with one is magical.
“They can do stuff you would never imagine, and also have the imagination to think of things you never would“