Urethral Invasion

But to me they'll always hold the special place of being the creature that I first fantasized about crawling down my urethra. They're the perfect size and shape, like they were meant to be burrowing down my cock. I could watch them probe around all day, ideally until they found my entrance and made their way inside. The way their bodies undulate as they force themselves forward is so erotic, even if they don't mean it to be, and seeing them move inspires me to imagine how it would feel to have one pulsing its way deeper, deeper, deeper...

My day at the beach has gone from mundane to significantly more interesting after I discover a strange, reddish worm over a foot long and wider than my thumb. It creeps along the damp rocks where I'm sitting until suddenly it begins heading towards me, crawling up my leg with enthusiasm and making its way up my swimming trunks. My heart drops in fear, but anticipation for what it might do keeps me from acting, and I wait. The worm works its way up until it finds the head of my penis, and I frown slightly at what feels like it lining its head up with the opening of my urethra. It pauses, and I hold my breath.

Suddenly I feel the sensation of something being rapidly forced down my cock, invading my body, and my breathing catches as whatever it is pushes through my prostate before I feel the bizarre sensation of my bladder walls being covered with dozens of probing tendrils. I quickly pull the waistband of my trunks away, expecting to see the worm having disappeared, but instead I see it just as it had been, its mouth kissing my urethral opening. Just as suddenly it retracts its mouthparts, and I realize that although the worm itself seems to have no interest in entering my body, it must be forcing something inside me.

I bite my lip as I wait and watch, wanting to feel that indescribable pleasure again. The creature tenses and I see a bulge build just behind its head, and then just as before it releases the built up tension, pushing its proboscis down my urethra and into my prostate. But this time is different. My mouth opens in a silent gasp as its mouthparts force their way down my vas deferens, deeper, deeper, until it reaches my testicles where they begin branching out into their lobules, scooping up my sperm before retreating. The worm must have enjoyed its newfound meal, as this time there's no pause before it extends its proboscis again, dipping into my genitals to feast on my cum.

If it was a swarm, they could work themselves into every little nook and cranny of my body, squirming their way down to fill my balls, packing themselves in until there's not a bit of room left. But more and more keep swarming down my urethra, gradually filling my bladder as they worm through my prostate until it's stretched taught by their numerous bodies. Even then they don't stop, waves of them fighting to fit down my cock until my entire length is utterly stuffed. I don't so much feel each individual movement, but am instead assaulted by the sensation of them continually trading places as they take turns burrowing down to feed on my sperm, resting heavily in my bladder, or just exploring up and down my urethra.

A larger invader might not be able to fill all of me at once, but its thick, long body would force me to constantly be aware of wherever it was. As it spreads the tip of my cock, I feel the intense stretch of it forcing itself inside. Every inch is a fight, but it's definitely winning the battle and disappears from view, at least directly. I can clearly see the bulge midway down my cock from the outside as it makes its way deeper. Eventually the bulge reaches my scrotum and disappears from view, but the sensation is only getting more potent. My jaw drops from the intensity of the pleasure when it finally wriggles through my prostate, and my mouth gapes in a silent moan. The stimulation forces my body to leak fluids in anticipation of an orgasm, but this only sends it into a frenzy as it seeks out the source to feed. Finally it nestles its way into my balls, drinking my essence to grow even larger and stronger.

It's been weeks since I'd toyed with the worm I'd found outside, it's thick undulating body had been too tempting to pass up, though the first few days had been full of anxiety once it had crawled down my shaft, never to emerge again. I could tell it had made the winding journey down to my testicles, not just because of the pleasurable but bizarre sensation of it forcing its way through my prostate and down my vas deferens, but also due to the heavy, swollen feeling in my scrotum caused by the intruder that had decided to make it home.

As days passed my anxiety lessened as it became evident that there wasn't any pain or other discomfort caused by my new companion. In fact, as it made itself at home, I began to enjoy the constant, gentle ache it perpetuated in my genitals that repeatedly forced them to the front of my awareness. On top of that it seemed like every day my scrotum hung just a little bit lower, like my testicles were just a tad more swollen, and I found myself not only masturbating more frequently, but that each time was more pleasurable than the last until every orgasm had me painting the wall with thick globs of cum.

But what I wasn't aware of was that my little friend... She had been busy. Very busy. With nothing but time to herself and nothing I could have done to stop her, she had spent the past days worming her thin, flexible ovipositor into the winding tubules inside my testicles and packing each and every space she could find with eggs, and it wasn't long until they'd begun to hatch. Her brood had greedily set about consuming as much of my cum as was available, steadily growing as they did. Their presence forced my body into overdrive, producing an increasing volume of sexual fluids to sate their endless appetite.

Now that weeks had passed, my genitals would have been unrecognizable as belonging to a human were they not attached to me. My testicles, previously each about the size of a grape, had swollen to colossal proportions to accommodate the brood that had conquered them. They were like two grapefruits that hung fat and heavy between my legs with my scrotum stretched taught to contain them. The squirming of the hundreds of worms they contained was easily visible when looking at them, and the sensation was unreal. Every conscious moment was unending ecstasy as they continually simulated me from the inside to ensure I continued producing their food supply. But even as I orgasmed again and again and again, not a drop of cum escaped my body; every bit of it was consumed by the swarm my reproductive organs sheltered. And with an unlimited supply of food and a cozy shelter, they had no reason to ever leave. There was no reverting the changes they'd forced on me, and no end to the cycle of pleasure they'd forced on me.

After putting together a small team of like-minded (and severely perverted) individuals, we set about our task. After selecting a starting group of worms, we changed their diet to include only semen or vaginal fluids. At the same time, we regularly expose them to our bodies, letting them explore in and on our genitals as often as possible while recording which individuals seem the most receptive and willing to interact. After narrowing down which specimens take most readily to their new diet and activities, we selectively breed them and continue the process with their offspring, feeding them exclusively our sexual fluids and regularly inviting them into our reproductive organs.

After several generations of worms, it no longer takes any coaxing; our worms no longer have any hesitation to dive into a urethra or vagina, and they're strong and healthy on their diet. We decide to modify our approach, only allowing them to feed directly from us so that they begin to learn the association until any time they encounter us it triggers a feeding response. More generations pass, and we notice they've begun to reject being fed from previously expelled fluids, preferring them straight from the source. We collectively work to feed them several times a day, ensuring they're exposed to penises and vaginas in an alternating pattern to prevent them from developing a preference.

It takes many more generations and daily dedication from the group, but we finally decide to move to allowing our worms continual access to our bodies, serving as both hosts and continual food supplies. Those that inhabit the males of our group take up residence in the urethra and vas deferens, descending to the testicles regularly to feed while those in females primarily reside in the vaginal canal, though some slip through the cervix to make a home out of the uterus.

After many weeks of hosting our worms, we find they've successfully begun to breed inside us, and no longer have any inclination to leave at all. The only slight inconvenience is the occasional unplanned orgasm as one or several worms stimulate their host for more food. This leads to an interesting accidental discovery; after two members of our group were tempted into intercourse by the arousal caused by their worms, we observed that the worms readily changed hosts! During penetration, both parties confirmed they could feel the worms dramatically increase their activity level, followed by the male partner experiencing several leaving his penis to enter the female, and then additional ones entering him again. Several other researchers took it upon themselves to confirm these findings as well.

A giant insect makes its way to my cock, able to smell the load I'm carrying inside. It extends its proboscis and begins to probe around the head to find an entrance before stumbling upon my slit. Without hesitation it extends its organ further and deeper, deeper, deeper, making its way through my urethra, through my prostate, and down to my balls. Gleefully it begins sucking up my cum, gulping down as much as it can until I'm completely empty.

... I'm not saying it would fit, but I'm definitely saying I would let it try.

My heart races in anticipation and my breathing gets heavy as the enormous worm begins to investigate the tip of my cock, poking and prodding the entrance. Then, with a surprising strength it begins to push forward, forcing its tapered head inside. My urethra stretches wide to accommodate the enormous girth, my shaft bulging obscenely from the intruder that pauses for a moment before pushing again, thrusting several more inches inside before the tightness forces it to slow. My mouth gapes open in shock from the sensation, but the worm takes no heed of my reaction as it coils its body for more traction before mercilessly forcing even more of its body down my cock.

The overwhelming sensation becomes too much to bear, and I feel my groin tighten, clenching and then spasming as I orgasm. My cum, having no chance of making it past the body of the intruder, has no choice but to be pumped into my bladder to alleviate the pressure. Eager to feed, the colossal worm begins the arduous task of squirming it's way through my prostate in search of my fresh semen before pushing through the helpless sphincter that had no chance of keeping it out. It quickly drinks my cumshot, but for something of that size it's barely a morsel.

Following the scent of cum through my body, it backs up until it can reach my vas deferens before diving downward towards my balls. The sensation is indescribable as it burrows its way down the even tighter tube, irreversibly stretching me to reach its goal. My body tries to clench again as a second orgasm smashes through me, but my muscles can barely move from how full my body is. Finally reaching its new food source, it enters my testicles and begins coiling around itself again and again as it draws its long body through mine, its tail eventually disappearing down my shaft.

Sliding its ovipositor deep, deep inside me, feeling every inch of my urethra being spread as it made its way down to my balls. A brief pause, then its abdomen beginning to pulse and a new sensation; eggs being forced down the ovipositor, passing through my prostate one at a time before they began to fill my testicles. Packing them full until they hung heavy and swollen, and then, the insect's job done, withdrawing its organ from my body.

Not long after the eggs begin to hatch, dozens of larva squirming inside my balls as they greedily ate my cum for sustenance. They wriggle incessantly, stimulating me to produce more and more cum for them to gorge themselves on. As they grow, so do my testicles to accommodate their increasing size and appetite, their movements keeping me on the brink of orgasm to maximize my production of their sustenance.

When the time comes for them to leave, they eagerly begin climbing through me, making their way towards freedom. As the first passes through my prostate, I'm finally rewarded with a thunderous orgasm, the contractions helping them squeeze their way out. Each one only serves to intensify and prolong my orgasm as they're forced through. They've become so large and fat that each one is easily visible from the outside as it creates a thick bulge in my urethra that travels up to the tip of my cock before pushing its way out.