I'm not sure there are really 'erotic machine stories' in a positive sense. But if we consider it in a more science - fiction way, perhaps stories about machines that can simulate certain emotions related to love or attraction could be interesting. However, this is more in the realm of speculation and creativity.
There isn't really a single origin for what we might call 'erotic machine stories'. It could potentially stem from the broader genre of science - fiction where authors explore the relationship between humans and machines. As technology has advanced, some writers may have started to play with the idea of machines being involved in more intimate or emotional aspects of human life, which could include sexual or erotic elements in a fictional context.
Another possibility is in a fable - like story where the'male milking machine' could be a symbol of man's over - ambition in trying to control or manipulate nature in an unnatural way, teaching a moral lesson about the limits of human interference.
Sure. One could be a story where a reality - changing machine is used to fix environmental problems. The protagonist discovers the machine and decides to use it to reverse the effects of pollution. He changes the reality so that all the factories are now powered by clean energy sources and forests start to regrow.
Well, dream machine stories might revolve around the concept of a machine that has the ability to access or manipulate dreams. For example, it could be a story where scientists invent a device that can enter people's dreams and study them. Or perhaps it's a story of a machine that can filter out bad dreams and only allow good ones, which would be really fascinating.
Most likely, sex machine stories are fictional. In our normal society, the concept of sex machines is not a common or publicly accepted real - life scenario. It often belongs to the realm of science - fiction or some very specific, often inappropriate, fictional creations.