Work Text:
A week after the eggs have hatched, Isaac is disappointed to find out that it will take months for the creatures to grow large enough to breed Duncan again. Already he misses the other man's rounded figure and pained cries.
It only takes a small bribe to the palace's physician to get his chance at recreating some part of it.
When Isaac enters the exam room, Duncan is laying on his back with his feet in the stirrups, wrists and ankles bound with leather straps to hold him still.
Isaac can hear the other man exhale a curse as he sees him before relaxing against the table in submission, knowing that whatever the prince has in store for him, he has probably had worse.
Isaac is pleased to note that Duncan's hole is still puffy and swollen from the birth, he looks well used and Isaac can't wait to give him even more.
Isaac coats his right hand in lube and rubs gently over the other man's abused rim before forming a fist and punching inside, knocking the breath out of the other man, who gives a shout of protest as the prince continues to press forward, pushing in as deep as he can go.
"Oh, hush," Isaac says. "I've seen what you can take, one measly little fist is nothing to you. I'm just getting started."
Isaac eases in his other hand as Duncan squirms on the table, pressing both arms forward until he is buried elbow deep inside, enjoying the view of the other man's belly bulging outward as he presses up against it from the inside. He grinds his dick against the table, not wanting to blow his load before he gets to the rest of what he had planned for the man in front of him.
He reluctantly pulls his arms out, watching as the ruined hole in front of him tries weakly to clench against nothing as he turns to open the cabinet where he stored his supplies for the evening. He pulls out a basket closely resembling the one he placed the eggs in for the journey home.
"You carried those monster eggs beautifully, it would be a shame to leave you empty until the hatchlings are ready for you," he says, pulling a large wooden ball out of the basket. It's polished surface gleaming under the overhead lights.
Duncan's eyes widen, "You can't! It won't fit!" he says in a panic, thrashing in his bindings.
Isaac shakes his head. "Don't lie to me, I was there when you birthed the eggs, I know exactly what that greedy ass of yours is capable of," he says as he slicks up the ball and presses it against the other man's rim, watching as the hole opens up to swallow it, and pressing it deeper until it is fully seated inside the man.
He pats the bulge of the man's stomach appreciatively. "There, I told you you could do it. You carried thirteen eggs for those monsters, surely you can do better for a prince."
Duncan shakes his head frantically as Isaac begins to slide in the second ball. Each one is the size of the eggs at birth and painted and polished to match.
Each ball goes in easier than the one before it as Isaac pushes them in, sometimes pausing while a ball has him stretched around the widest point, holding it there and stretching his rim further with his fingers.
"I read your chart you know," he says slipping in another ball. "You never told me you had been enchanted to stretch to accommodate anything without tearing. Instead of pulling you apart, your body simply adapts and expands to take what it is given. Very complicated spellwork. That's how you're able to survive breeding with the creatures. I can't help but wonder why the scientists stopped at filling you with one clutch at a time, why not continue testing to see what your limits truly are, if you have any at all."
"It won't tear me, but it still hurts to get stretched so far, the enchantments didn't change that," Duncan says through choked sobs.
"Your pain is none of my concern, I just wouldn't want to break my new favorite toy, at least not so soon," Isaac says nonchalantly as he reaches down to retrieve another ball from the basket. Fourteen, one more than was given to him by the creatures.
Isaac stands back to admire his handiwork, the other man's stomach is huge and rigid, marred by angry red stretch marks. His asshole is open and twitching, the worn out ring of muscle not even attempting to close anymore, and the final "egg" still visible inside.
Most curious is the other man's cock, standing upright and begging for attention. "I knew you were a slut," Isaac says reaching forward to run one finger up the other man's hard cock. "You just can't get enough, can you?"
"I've had enough, I swear," he says pulling away the small amount that his bindings will allow. This movement jostles the final ball inside him, causing it to nearly slip out. Isaac catches it and presses it back in as Duncan suppresses a groan.
"We can't have any premature births," Isaac chides. "If you can hold them in for the monster, you can hold them in for me. Now hold yourself open so I can fertilize the eggs," he says, laughing. As if the other man even has a choice in the matter.
Isaac lets out a groan of relief as he frees his cock from his pants, pressing into the open hole in front of him. It is almost comical as he looks down at his cock, not even touching the walls of the cavernous opening.
This is even better than the whores he usually hires. He loves to watch them squirm as he fucks into them roughly with no preparation, but his favorite part is after he comes, just as they relax on the bed believing it to be over, he presses in with his fist. The screams he gets from those encounters are just divine.
Once a man sought to trick him, having already prepared himself before arrival, the surprise and pain on his face as Isaac pressed in a second hand provided Isaac with enough material for an entire month of jerk-off sessions.
Even that was nothing in comparison to the man in front of him, he thinks as he reaches down and grasps his cock, fucking his fist inside the man and coating his insides.
He steps back and tucks himself back into his pants. "You are to hold my eggs in until I say it is time to birth them, any eggs that are birthed prematurely will be replaced by two more, and time will be added."
"I can't hold them in!" Duncan says, panicked.
"I suppose I have something that could help you," Isaac says, reaching for the last item in the basket, a deceptively small ornately carved plug.
"What's that supposed to do?" Duncan asks, huffing out a pained laugh.
"You'll see," Isaac says, slipping it in.
The plug immediately begins to expand as Duncan squirms on the table.
"Enchanted to fill anyone just right, one of my favorites," Isaac says, thinking back to the last man he used it on. He made the man wear it for hours every day for months until it had finally grown large enough to leave him ruined for anyone else.
It is designed to push limits. Isaac loves the idea of his whores only being useful to him. He has never needed a tight hole in which to sink his cock, preferring instead to jerk himself to the sight of men being ruined. Enchanted toys, greased cones, his own fists, it was all leading up to the man in front of him.
The plug continues growing until the man's pelvis, already expanded to fit the eggs inside, creaks from the pressure.
Tears well up in Duncan's eyes but they don't fall as Isaac removes his bindings and pulls his feet from the stirrups. Smiling to himself as he notes the other man's inability to fully close his legs.
He walks back to the cabinet to retrieve the clothes he had stored there. Plain peasant's garb, the shirt more of a tent than anything else, strongly resembling what he wore on the trip to the castle. The pants have a slit cut up the back so that everyone can see just what this man is good for.
Over the next three weeks, Isaac visits Duncan nightly in his quarters to make sure he is following his instructions and the "eggs" and plug are still firmly in place. After the first week he is pleased to note that Duncan's pelvis was not the barrier he expected it to be, the stretchy properties of his body extending even to his bones, allowing the plug to continue to expand with time.
Each night after his exam, Isaac fucks roughly into Duncan's mouth and gives his cock just enough attention to leave him hard and desperate, unable to reach it over his swollen belly, promising a reward once this is all over.
Finally the day comes for Duncan to lay the eggs, having held them in one day longer than the eggs he carried for the monsters. Isaac finds him once again strapped on the medical table with his legs spread and his feet in the stirrups, unable to move from his position on his back.
Isaac retrieves the syringe left for him by the doctor, and injects the substance into Duncan's veins. "This ought to kickstart your labor," he says, taking a seat across the room with a good view between the other man's legs and pulling out a book to read.
"Aren't you going to remove the plug?" Duncan asks, wincing as the first contraction hits.
"And have this be over so soon?" Isaac asks with a laugh. "I can't make this too easy on you, where's the fun in that?"
Hours pass as Duncan is left writhing and crying on the exam table while Isaac continues to read his book. Isaac observes with interest as the plug is nearly forced out by the pressure only to expand again to reinforce its hold.
Finally, after Isaac has finished his book he approaches the exam table and pulls a measuring device from his pocket to measure the final girth of the plug before its removal.
"Now what are you doing?" Duncan asks through gritted teeth as he is wracked by another contraction.
"I fear the use of the plug may have made this too easy on you. I'm simply seeing what size I should make the eggs for your next clutch. I fear if I use the same ones again they will only fall right out." Isaac says, gripping the plug to remove it. It shrinks down in his hand before being placed with the other supplies.
"Of course that's it, I'm sorry I asked," Duncan says, rolling his eyes as he relaxes momentarily against the table before being hit with another contraction. This far into his labor they are coming very close together.
Isaac watches as not one but two eggs make their way toward Duncan's open hole. Despite being so open it still takes a good push before they emerge side by side, ready to be caught and placed in the basket. Without the aid of gravity, pushing them out is an ordeal.
Slowly the rest of the eggs make their way toward Duncan's destroyed hole. At one point three attempt to exit simultaneously and Isaac thinks for a moment that the man in front of him may not actually be invincible before one slides back in allowing the other two to fall.
When only five eggs remain, things stall. They are too high up to be pushed out without the aid of gravity, at least with Duncan's muscles as exhausted and stretched out as they are.
Isaac tugs the straps of the exam table loose and forces Duncan to his feet on shaky legs. It has been weeks since he was properly mobile and his current state of exhaustion is no good way to start. The expansion of his pelvis has changed his gait and the pain going through his body makes it hard to concentrate on his footing.
Isaac forces Duncan back into his clothes, admiring the view of his ruined ass through the slit in the back of his pants as he walks him out of the room and down the hall. He is pleased to note that with every step the bulge in Duncan's abdomen gets lower, movement and gravity working together to allow the wooden balls to move downward toward his hole.
As they walk through the corridors they attract attention from curious bystanders. Isaac smiles at the attention, forcing Duncan to get on his hands and knees while he makes a show of examining him to see if the eggs have made it any closer. He puts his hands through the slit in Duncan's pants and pulls his hole open with both hands to get a visual on the faux eggs remaining inside and give the audience a view of just how debauched his new toy is.
All five eggs are nearing the exit, so Isaac presses his hand into Duncan's belly, forcing them down even further until the first one begins to crown. Isaac takes that moment to force Duncan back to his feet just as it slips free and falls to the ground. Isaac decides to leave it there, having no use for an egg this small in the future. Perhaps someone from the audience would like it as a souvenir.
When they arrive back at the exam room, only one egg remains. Isaac bends Duncan over the table and slides his hand into the swollen ruined hole, forcing the egg out manually. He decides to make the next eggs even heavier, both as a challenge to hold in and to aid in the birth when the time comes.
Before Duncan can finish breathing a sigh of relief that it is over for now as he relaxes against the exam table, too exhausted for the walk back to his room, Isaac forces his feet back into the stirrups and closes the bindings around his wrists and ankles once again.
“Now, I believe I promised you a reward,” Isaac says with a grin as he pulls an ornate wooden case out of the cabinet.
“That’s okay, you can keep it,” Duncan says, clearly wary of whatever is in that case.
“Don’t be silly, I know you’ve been wanting me to pay more attention to your cock, and I’m getting bored with your mouth, so really this is for both of us.”
“Well I can reach it now, so that won’t be necessary,” Duncan tries to argue, eyes widening as he sees what’s in the case. A variety of metal rods, each slightly thicker than the last. Interspersed with hollow tubes of the same thickness. The final one is nearly as big as a cock.
Isaac had these specifically commissioned. Just because he doesn’t need a tight hole to fuck, doesn’t mean he might not sometimes want one, and it isn’t as though Duncan’s ass is going to be serving that purpose any time soon.
He takes a moment to stroke Duncan’s cock to full hardness, amused at how easy it is despite the other man’s protests, then slides the narrowest one in, not meeting any resistance as Duncan shudders from the brand new sensation.
“That was far too easy,” Isaac says. “I thought this would take all week, but perhaps we are already ahead of schedule.”
Isaac slides the first rod out and moves on to the second. This one meets only the slightest bit of resistance as Duncan groans. Isaac slips it out and replaces it with the third, this time feeling far more resistance as Duncan squirms and bites back a scream. This is the one.
Isaac mercilessly fucks Duncan’s cock with the rod, stroking him back to hardness every time his erection begins to flag. Once he is satisfied he replaces the rod with a tube of the same thickness to hold him open.
“If you promise to leave this in, you can go back to your room. If not I will keep you here and tied down until I finish.”
Duncan nods, at this point he is willing to do anything to get off this table before Isaac has any more ideas.
Isaac fastens the tube in place using a cock cage and unfastens Duncan’s bindings, allowing him to slowly get dressed and limp down the hall.
Isaac visits Duncan twice a day after that, each time moving up a size as he continues to fuck him open on the metal rods. Late in the evening on the fourth day he reaches his goal.
He carefully places the final rod back into the case and lubes up his cock, grasping Duncan in one hand and himself in the other and slowly guiding his cock through the obscenely stretched hole, watching as it bulges from the intrusion.
Once he is fully seated he begins to stroke himself through the other man, it’s like nothing he has ever felt before. He can’t believe he hasn’t tried this sooner. “How do you feel now that I’ve turned your cock into a cock sleeve?” he asks as he begins to pull back before thrusting forward quickly, slowly building a steady rhythm.
“Not great, honestly,” Duncan answers through gritted teeth.
“That’s a pity, I’m quite enjoying myself,” Isaac says, picking up the pace. He isn’t going to last long, the combination of seeing the other man’s discomfort face to face, knowing he has ruined him and the tight slick opening he is sinking his cock into is almost too much. He presses in as far as he can and comes harder than he ever has in his life.
After a moment he rolls off and sifts through the box for the largest tube and fastens it into place taking a moment to enjoy the sight of his come dripping out of the other man.
As he leaves to think up the next thing he wants to try, the one thing he knows for sure is that he is just getting started.