The sensuality of a machine
Note: While this webpage doesn't have any strictly nsfw images it contains mildly nsfw text.
I suppose there are a few factors that might make a machine appealing to a human. For autistic or some otherwise neurodivergent people direct, skin-to-skin contact with other humans might be uncomfortable and unpredictable. Additionally many such individuals enjoy stimulation involving weight, such as weighted blankets, so natuarally an atraction, be it aesthetical or even sexual, towards large machinery might develop.
Honestly I don't think that there is a "right way" to be into robots and/or machinery (just maybe don't act it out in public in a non-OSHA complient way); this page will mostly be about megastrutures and people dwelling in them.
Megastructures
To put it simply - a megastructure is a very large artificial object; a product of megascale engineering. The specifics of what is a megastructure vary but in most fiction these tend to be at least the sixe of a city meaning that they still don't exactly exist in our current time. Additionally a megastructure should be self-sustainable and able to have humans live inside. In fiction megastrutures are often spaceships or transformed planetoids.
In sci-fi works these often have some sort of artificial inteligence that governs it. As is the nature of AIs in fiction they often go rogue.
Fictional machines
GLaDOS
Aparture Sciences buildings can be by all means considered a megastructure. Most of it lies underground, save from the Combine, and slowly decays while GLaDOS lies 'dead'. There is something very appealing about the idea od Chell crawling around in GLaDOS'es body. Everything she interacts with, including turrets who speak with Caroline's voice, is in some way a part of GLaDOS. No doubt the game ends up strongly implying some sort of romantic relation between her and the protagonist. Even when Chell leaves, she takes the Companion Cube with her.
Citadel
The Citadel from HL2 lacks a charismatic AI (whose role is replaced by dr. Breen) making the structure feel much more like a hostile parasite on the human city. You get the feeling that you are not supposed to be here because there isn't supposed to be something alive there at all. Even Breen doesn't look like a part of this structure, with his very human outfit and very human office. The Citadel is a mega form of hostile architecture.
AM
In the game (and the short story) I Have No Mouth But I Must Scream, the evil AI called AM has a control over the entire Earth making it a sort of megastructure. AM, being created to plan wars, is in a way a personification of the evil of human race. Thus he poisons the Earth. AM also has a deep hatered for his creators making the world that five remaining humans are forced to live with hell, much like war makes earth hell for the living.
Metal Garden
Metal Garden is a short fps game presenting a somewhat diferent approach to the genre - here the megastructure is so ancient it becomes a world out of itself. It's a megastructure which, while artificial, just like any other planet, has to real purpose to it. Just like the protagonist, this world just is, ever going forward, not minding the political disputes that pass it by. In Metal Garden there is no destinstion, only the journey
Other fictional megastructures include Dyson spheres (which appear in many sci-fi worlds), titular Halos from Halo series, enormous spaceships such as Almighty from Destiny 2 or variours structures available in Stelaris.
Machine planet
One night I had a dream of a machine planet. It was sort of like a Borg cube but created from a planetoid. The galaxy was old and mostly empty. It was a sundown of an universe.
There were people on this planet; mostly living under the surface to protect themselfs from the radiation of their dying star. Some had to live on the surface to barted with rare visitors. They would wear black rubber suits to protect themselfs and the visitors had religious garbs. The people of the planets were considered deviants and mutants, it was dengerous to be a surface dweller but some had to.
Those who lived underground were safe from the dangers of the dying civilization. They would burrow there, drilling and building their megastructure. Like moles digging their tunnels. Eventually there would be no visitors anymore. Wihout a way to messure times, the community of the planet would be eternal.