I walk into my dark bedroom naked and I hear a wet wriggling sound. Before I know it, two 4 small tentacles take each of my limbs and makes it so I can’t struggle.. then a larger tentacle starts to probe my asshole and slowly enters my ass and goes for my prostate. A larger hollow one swallows my cock and starts to suck as two small ones massage my testicles and inject a chemical that makes me cum endlessly. As I hit ecstasy, I cum so much that the tentacle fills up. Then a female alien who controls the tentacles says I’m a good boy for feeding her. She rewards me by letting me drink her milk which makes me really horny. The female alien grows a cock and starts to fuck my ass as I keep cumming. Basically I’m a sex slave.
Source: reddit.com/r/Erotica/comments/nu5eqs/could_someone_take_this_premise_and_make_it
I always like stories where the main character is at least partly complicit in their predicament. So rather than jumped in your room I would do hiking and found a plant with a flower that looks like a pussy. Decide to fuck it and it sucks your dick in. Tentacles come out but you cant get away with your dick trapped. Tentacles start grabbing you and fucking you in the ass. Spiney pods latch on to your balls and make them swell to three time normal. Tentacle cock pops in your mouth and feeds you nectar to keep you pumping semen. Alien futa comes and collects her trapped new toy.