"""
[…] and I opened the case (politely examined by the guards of the Palace at four stages of my approach to the Red Hall) that held my ansible and some pictures. The pictures—films, photos, paintings, actives, and some cubes—were a little gallery of Man: people of Hain, Chiffewar, and the Cetians, of S and Terra and Alterra, of the Utter-mosts, Kapteyn, Ollul, Four-Taurus, Rokanan, Ensbo, Cime, Gde and Sheashel Haven … The king glanced at a couple without interest. “What’s this?”
“A person from Cime, a female.” I had to use the word that Gethenians would apply only to a person in the culminant phase of kemmer [a cyclical period of heightened sexual activity during which secondary gender characteristics emerge], the alternative being their word for a female animal.
“Permanently?”
“Yes.”
He dropped the cube and stood swinging from foot to foot, staring at me or a little past me, the firelight shifting on his face. “They’re all like that—like you?”
This was the hurdle I could not lower for them. They must, in the end, learn to take it in their stride.
“Yes. Gethenian sexual physiology, so far as we yet know, is unique among human beings.”
“So all of them, out on these other planets, are in permanent kemmer? A society of perverts? So Lord Tibe put it; I thought he was joking. Well, it may be the fact, but it’s a disgusting idea, Mr. Ai, and I don’t see why human beings here on earth should want or tolerate any dealings with creatures so monstrously different. […]”
"""
(Ursula K. Le Guin, The Left Hand of Darkness)