Fear-Hole

It doesn’t matter whether or not the poor fellow can breathe while the first slime squelches down his throat, seeking the security of an enclosed space to use for incubation. When the guy puts a hand on his throat to try and rub away the discomfort on instinct, he can probably feel the swell and bulge of a thick slimy tendril expanding into his stomach, making him swell. His body gets heavier by the second as more and more of the thing sloshes into him, filling him up, rounding him out.

The one exploring his cunt doesn’t help matters, either. It can easily squeeze past his cervix and force it wide open around itself, filling his womb as it shoves almost its entire form into the poor boy. Thick fluid gushes into his tubes to explore all of the available room, and the slime is likely delighted to find fertile material for fuel - slimes can reproduce all on their own, of course, but using a host’s own reproductive system against it can decrease the necessary energy output. The boy is forced to confront the horrible sensation of his ovaries themselves being engulfed, squeezed, explored, shifted inside of him, raped in a disturbingly complete way.

The one in his ass can easily navigate the maze of his guts, stretching him taut from the inside out, pressing every single part of him up against the others. The sheer pressure makes him piss himself, but the slimes are undeterred; the liquid, in fact, seems to rehydrate the entire system of slimes somewhat, making them shudder and thicken inside of him. He can’t make a sound, but he’s in more pain than he’s ever been before - and the thin tendril that makes its way up his pisshole a second later only makes it worse, entirely alien and unfamiliar to him, squishing inside and increasing the already-unbearable pressure.

He’d almost forgotten about the third slime, but it makes its presence known by delicately exploring his outer ears. He knows what it’s aiming for, and desperately thrashes his head, trying to escape, trying to shake it off, but to no avail. All sound from the outside world is blocked as slime easily flows into his ear canals, past his eardrums, deeper and deeper until it meets the soft surface of his brain, flowing into his skull and absorbing the cerebrospinal fluid to fuel itself. The horrible headache that results only lasts for a second, however - the slime, seeking further asylum for its eggs, plunges into his gray matter directly, flowing across the entire surface and spilling into every crack and crevice before proceeding deeper, severing connections that used to make him human, pushing everything out of the way to make room for itself and its young.

Now that his brain is being physically interfered with, the victim of the slimes’ escapades can hardly tell that any of this is supposed to be painful. In fact, it seems like quite the opposite - waves of pleasure start building from all across his body, originating deep inside to flow outwards and set his skin alight. The stimulation that was once agonizing spills over into ecstasy, chaining together orgasm after orgasm, his toes curling, his eyes rolled back in his head as he rubs his own clit furiously, masturbating as the slime rapes every semblance of humanity out of him.

The first two slimes had gotten started before the third, so they’re finished first. Their withdrawal hardly seems to make a difference in the boy’s swollen state - they trail hundreds, even thousands of eggs in their wake, making sure every inch of their victim’s insides is full to the absolute brim. Stomach, guts, womb, bladder, throat, he can hardly breathe because of the eggs threatening to come out of his mouth, but he doesn’t care. He’s too busy cumming again, and again, and again, twitching violently at every touch from the slime in his brain. It sloshes and swirls in his cranium, obliterating everything that could be considered human and leaving just the basic functions in place - as well as the arousal, the desire to stay completely full of eggs and slime, the desire to bear young.

Slime eggs replace his brain with ease, creating a pleasant, almost floating pressure inside of his skull. He’s left alone on the ground, every hole gaping and slimy, sloppy, open to use for whoever wants to find him next. If anyone just so happens to come across such a readily-available set of holes and makes use of him, however, they’re not going to leave him pregnant - the slimes already did that. He’s probably going to cum even harder when he has baby slimes pouring from every single hole in an endless wave of invasion and pleasure.