thinking of slime permapreg...
Imagine a novice mage, out in the forest to gather spell components. Crouched down, picking herbs, not keeping an eye on their surroundings. They're barely a mile into the forest, nothing dangerous would risk getting this close to civilisation.
Nothing dangerous would, but a slime might. They don't have brains after all, operating only on instinct. Mostly, these instincts are "consume, multiply, defend". They eat until they're big enough to split in two, and they fight anyone or anything trying to keep them from these two tasks. There are other species though, too small to fight, and too stupid to do anything but find a warm, small place to lay their eggs.
Such a slime just happened to be among the plants where our young mage was foraging. Sensing their warmth, the slime slithered beneath their robes and up one leg.
At the first touch of cold slime on their bare skin, the mage shrieked and dropped their basket, snatching up their robes to find a blue-ish slime, barely big enough to fill a cooking pot. They breathed a sigh of relief, not feeling any acid or constricting arms, and shook off the slime. While they were reaching for one of their textbooks on the forest floor, the slime immediately resumed its mission.
The book told the mage that they had just met a harmless slime, one of the egg-laying species. Quite harmless, and rather rare. Mainly because its eggs had potent magical properties, but it was hard to cultivate the slimes in captivity and the wild ones had been hunted nearly to extinction.
Immersed in their reading, the mage thoughtlessly wiped the slime from their leg a few more times, until the cold sensation had become background noise. They were so engrossed that they paid no mind to the outside world at all, until they felt a wetness between their legs. The slime was pushing against their crotch. The mage froze for a few agonizing moments, feeling the slime moving with clear intent, and then looked down at the paragraph they were just reading. The one about slime reproduction, and how many had failed to deduce the exact method to grow and harvest these lucrative eggs. No one had thought to incubate the eggs themselves, though.
No one until now, as the mage's mind was quickly filling with thoughts of a discovery that would make them famous and fill their coffers. A gold-filled womb that would launch their career. A filled womb... The thought did not repulse them as it rightly should, but instead sent a thrill through their body they had not felt before, not helped by the slime still bumping their increasingly slick groin. No one would have to know until they had results... If things went wrong they could take care of it and keep it quiet.
In a daze, almost unthinkingly (or so they later told themself), the mage crouched down as they had been at the slime's first touch and pulled their underwear down their thighs with trembling fingers.
Feeling slick skin, the slime started moving with purpose again, sliding between the mage's folds, over their throbbing sex, probing at their hole that was already leaking. The mage gasped and wobbled precariously, grabbing onto a nearby tree just in time to stay upright, and then stilled, not wanting to frighten the slime away. They needn't have worried, for it was already slowly pushing in, a sensation that was wholly unfamiliar yet maddeningly good.
Some small part of the mage's brain whispered about how the slime would fit, and whether it could even get all the way in, but the rest of them was lost in a fog of arousal and pleasure. The slime was filling them up, insistently pushing deeper, until the mage felt their orgasm wash over them, followed directly by a sharp pain and then a weight settling deep into their core. Cautiously feeling between their legs, they realized the slime was now fully inside, and sat down heavily in the grass.
Once the muscle spasms and the harsh panting had abated, they rose on their legs like a newborn foal, gathered up their things, and ambled home, still getting used to the new weight in their womb.
