Chapter Text
Eggman had been up to something - something that involved too many power signatures and suspicious energy readings in an abandoned industrial sector. That's why Sonic and Tails were in his base, working through corridors and security systems. Sonic hadn't been too clear on the details - whenever Tails said Eggman was up to no good, he just got a move on it.
These missions rarely varied. Show up, cause a ruckus, flip through some doors and destroy a bunch of bots, thwart the evil plot and get on with it.
But this time, Sonic slipped up before he'd even seen a single bot. Some sort of smoke filled the corridor he and Tails were in. They each hurriedly removed a glove to act as a mask, but then the floor opened up wide and they dropped down into the dark.
When Sonic woke up, groggy in the head, metal cuffs had been snapped around his wrists and ankles. His knees were on concrete, but they didn't feel heavy in the forward leaning position. His arms were supported even though they were stretched out above him. But his legs - his legs were anchored down tight behind him. He was stuck, no two ways about it. He tried to stretch but didn't find much give.
Crap.
"Sonic!" Tails' voice came from in front of him, sharp with panic. Then his vision came into focus and he twisted as much as the restraints allowed, only for his stomach to drop as he recognized bars.
Shit.
They were in cages.
Tails was in another cage - smaller, positioned at head-height directly in front of Sonic's face. Close enough that Sonic could see the fury in those blue eyes, the way his tails lashed behind him.
"Well, well, well!" Eggman's voice boomed through hidden speakers, gleeful and theatrical. "Caught like the pests you are! And now, for my latest experiment in behavioral modification. As soon as I press this button-" Sonic was already sweating. Eggman pressing buttons was never a good thing. "You'll be welcomed to a new you, hedgehog."
"Let us go, Eggy!" He hollared, feeling the weight of his compromised positioning as a low mechanical whir stirred up behind him, rolled forward with clicks and buzzes that never, ever, ended well.
"As I was saying," Eggman continued, voice dripping with pride, "this device is calibrated to measure stress responses and compliance in-"
But Sonic wasn't listening.
He was watching Tails, watching the anger in his eyes bleed into curiosity as the machine positioned itself. Watching the way those twin tails stilled, attention fixed on whatever was happening behind Sonic.
Then something warm and wet traced along his hole, circled it disturbingly casual.
Sonic's entire body went rigid. "What-"
The appendage - slick with lubricant, heated to body temperature - played with his balls, rolled them gently before returning to circle his entrance. Teasing. Exploring. The pressure was light, clinical, but the sensation was unmistakable.
Whoa, whoa, whoa, whoa
"Hey Eggman! No, absolutely not!" Sonic's voice pitched higher, panic edging into his words as he struggled against the restraints, rattled the cage and chaos flicked over his fur.
"Ah ah ah," Eggman tsked through the speakers. "I should mention - the machine is rigged to increase intensity with every protest. If you want this to remain... manageable... I suggest you shut up and take it till you cum like a polite hedgehog."
The mechanical appendage pressed harder, still not entering, just playing against the muscle. Little pulses of pressure that made Sonic's breath hitch despite himself.
Don't react don't react don't react-
"Oh fuck off!" The words burst out before the hero could stop them - instinct, defiance, the need to fight even when fighting made it worse. The dildo slipped in, warm and stretching, light and soft but disgusting all the same. It felt like real flesh.
Sonic's eyes squeezed shut, breath punching out as the foreign object pushed deeper. It was warm - disturbingly warm - and tactile and slick, and the sensation of in and out made his brain feel mushy, icky trying to process it.
But it... it didn't feel bad. Which was weird, he'd never once done this before - and it was the kind of thing that should have hurt. But it didn't hurt - it just felt weird, foreign, off. When he looked up, Tails' eyes were glassy, his chest was rising quick. Also abnormal.
"What was in that smoke earlier, Egghead?"
"Appetite wetters." An obscure response. They'd been drugged, probably to make whatever plot this was easier. Drugs that relaxed the body or lowered inhibitions or made getting stretched and filled feel interesting.
Sonic tried to bring his hips forward, tried to pull away from the thick intrusion, but the restraint’s positioning only helped it press in deeper. Worse. He moaned around it, to keep the string of curses threatening to spill out at bay. Talking dirty, reacting vocally to getting fucked would only give Eggman what he wanted. Would only make this escalate.
"What are you doing to him?!" Tails shouted, and Sonic's eyes flew open. The fox was pressed against the bars of his cage, watching Sonic's face contort in ways he'd never seen before. Watching his back quills flare as he arched involuntarily, body fighting the penetration even as the machine worked him open. "You're hurting him!"
"Tails - is there anything - ah - anything about your cage you can - can pick or-" His voice kept breaking on the sensation, hips starting to rock despite himself, caught between escape and the way the angle was starting to hit something inside him that made sparks shoot up his spine. He tried to ignore it, tried to focus on the fact Tails was free and could move around his cage, focus on the fact he at least knew where his brother was - grateful it was happening to himself and not the engineer.
Tails looked around frantically, trying to ignore the soft gasps painted blue in Sonic's voice behind him. Which was hard - impossibly hard - because he'd had a crush on Sonic for far too many years. The kind he should have outgrown by now.
"No Sonic, there-" he started.
"Fuck-" Sonic's protest dissolved into a gasp as the motor clicked into a higher gear, the dildo pumping faster now, still only halfway in. "Shit-" Sonic bit down hard on his lip. "It's tuned to you, too, Tails. Your voice-"
The machine thrust deeper, fuller, and Sonic's head dropped forward, breath coming in ragged pants. It felt... it was hitting his insides in the way that was filling his pouch out. A simple biological response, that was all. Sonic wasn't enjoying it, he wasn't.
But he was much less confused why Shadow was so willing to bottom for Knuckles, now.
Tails froze, understanding hitting him like ice water.
"How do we make it..." He swallowed the word stop. Thought frantically as Sonic's eyes fluttered with every thrust in, the tip of his cock beginning to emerge pink and slick and damning. Watched Sonic's knees knock together, trying to hide it, trying to maintain some dignity even as his body betrayed him.
He couldn't use negative statements.
"Eggman, what can I do to help Sonic?" Tails asked, voice tight and high, fighting his own demons down because his body felt weird too. He hadn't gotten his glove off as quick as Sonic, had inhaled more of the miasma, and he was starting to realize how it worked by the heat building in his gut, curling up like it wanted to take part too.
"Oh, you want to help the hedgehog?" Eggman's voice was thick with amusement.
"Y-yes, I want to help Sonic." Tails didn't like the sound of this. Didn't like the anticipation dripping from Eggman's tone, hated how soft Sonic's moans were falling out of his open mouth, how green looked defeated already.
"The best thing you could do for a chatterbox like him is to prevent him from saying any of the accelerator words. Perhaps..." A theatrical pause. "You should fill his mouth with something? Keep him occupied?"
Sonic's eyes shot open. "No - no, no, no!"
The machine responded immediately, fucking into him rough and full, hitting that spot inside that made his vision white out. His cock pushed fully from his pouch now - all five inches of it hard and leaking and mortifyingly not enough.
"T-Tails~" The name came out broken, needy, wrong. "You're better than that - you! I-I-I ah! - I want better for you-"
He was such a martyr.
Tails couldn't think. Not with this visual right in front of him, with Sonic so wrecked and his mouth open against the bars of his cage, drool starting to gather at the corner. Not with the way Sonic kept saying his name like that - pitched high and desperate and doing things to Tails' body he absolutely could not control.
"Tails, you're-" Sonic's gaze dropped, horrified. "You're hard!"
"A-and whose fault is that?!" Tails' face burned hot enough to hurt. His cock was already emerging, swelling between his legs, and there was nowhere to hide it, not with his size. This was so embarrassing. "You keep saying my name all weird!"
His cock was filling out, golden and peach, standing upright and twitching between his thighs like it had a mind of its own. Like the meal it’d been dreaming about since it learned to eat was made perfectly before it. Tails tried to cover himself with his hand, but it was impossible - thinking about Sonic made him get so big.
”Fuck! Make - make it stop," he cried, overwhelmed to the point he'd forgotten the rules. The machine fucked him rougher, till he was face against the bars and glowing with a full body blush, knees and elbows slacked against how full and fast he was being fucked.
He looks - God, Sonic looks-
"Will it really help Sonic if I do this?!" Tails called up toward the speakers, voice cracking, cock dribbling excitement.
"It couldn't hurt~" Eggman's voice was thick, probably getting off himself behind closed doors. The disgusting pervert. "I would have expected him to cum by now, but the pest can really take a cock. If you stimulate his mouth though, perhaps you'll push him over the edge. Or, if you cum down his throat, I'll turn the machine off as a reward."
Tails looked at Sonic - at the way his mouth hung open, panting, at the tears gathering at the corners of his eyes, at the way his cock leaked steadily against his stomach. At the way the machine kept taking him, kept pushing in and pulling out in a sickening pace, no gaps, no stalls, just pure rhythm, machine. Blue hips were splitting open wider for the peach dildo to hit deeper, despite his protests and sobs.
"Tails I'm sorry, I'm sorry, Tails~" But Sonic wasn't really there anymore. His eyes were glazed, body rocking back onto the machine despite himself, chasing the friction even as shame painted his features. Given over to sensation in a way Tails had never seen him surrender to anything.
Sonic liked getting fucked, and Tails would never unlearn that fact.
"Are - are you even close to finishing, Sonic?" He checked, looking for the path of least damage, unwilling to walk down the yellow bricked road if it was only to fulfill his own fucked up dreams.
Sonic whimpered in response.
Yes would have been the only thing he could have said and it would have been a lie. He'd never thought about sex much, hadn't had an interest in anyone in that way, so he didn't know. He didn't know and hadn't felt like he'd wanted or needed anyone before, before... he couldn't even finish the thought.
Sonic wasn’t close. Sonic needed more. And Tails didn’t want to know what happened if Sonic kept forgetting the rule. The fox stood at the edge of his cage, every rational thought screaming at him to find another way. He'd built interdimensional communicators from scrap. He'd piloted through temporal anomalies. He could solve this without-
”Tails, tails, tails, tails,” he was panting, reciting him name like a rosary, hope.
Sonic whimpered his name again, broken and needy. And again. And again.
Eggman had given the engineer the perfect out: do this to help Sonic. Noble. Necessary. Except Tails knew - knew - that wasn't why his hands were shaking as he reached for the bars.
"I'm sorry, Sonic," Tails whispered, walking forward to do the unthinkable. He fit two fingers through the bars to encourage Sonic's chin up, prompt glazed over, gone eyes to find his own, and slotted his nine inches through the gap in the bars, lined up with that wet, pink, silver tongue, allowed his tip to brush over Sonic’s open, panting mouth.
He wanted to cry, it felt so good, Sonic looked so beautiful. And between the emotion and the adrenaline, the shame, he was fully fleshed out, the biggest he’d ever been, and it was every bit his personal hell.
Sonic's tongue flexed at the new flavor, the salty musky scent, felt Tails get heavier in his mouth at the visual alone. Tails' cock was growing in his mouth, getting harder, bigger, thicker. Rim rod perfect, a performer through and through - and the weight did something to Sonic’s brain. Something new.
His cock pushed past Sonic's lips, sliding along that warm tongue, and Tails' vision nearly whited out from the sensation. Hot. Wet. Perfect. His length grew rapidly, elongating as arousal took over, pushing deeper until he felt the head brush the back of Sonic's throat.
They just stayed there, not even fully processing how fucked up it was, just desperate to help each other out of a terrible scenario.
And then Tails hips jerked, eager on his behalf without permission.
Sonic gagged - just once - eyes watering, but he didn't pull back. Couldn't pull back, locked in place by the cage, the restraints. His throat worked around the intrusion, swallowing instinctively, and Tails made a sound he'd never made before.
"Oh - oh fuck - Sonic-"
The machine kept pumping, kept hitting that spot inside Sonic that made his whole body shudder. And now his mouth was full, stretched around Tails' cock, unable to protest, unable to say anything that would make it worse.
Trapped between them. Filled from both ends. Taking it because he had no choice.
And the sick part was, it was helping. He hadn’t known his mouth would have so many nerve endings, hadn't considered what familiar pheromones would do to his system. Hated that it made the dildo feel really… really damn good fucking into him.
Sonic's eyes rolled back as Tails began fucking his mouth softly, pleasure and shame and overwhelming sensation reducing him to nothing. His cock throbbed untouched between his legs while his body learned to accommodate both intrusions at once.
And Tails - Tails couldn't stop staring at the way Sonic's lips stretched around him, the way drool leaked from the corners of his mouth, the way his throat kept flexing with each shallow thrust Tails couldn't quite control.
This is wrong this is so wrong we shouldn't-
But Sonic's tongue was working against the underside of his cock, and his throat kept swallowing, and the visual of him taking it - taking both of them - was burning itself into Tails' brain in ways he'd never be able to forget.
"Good boy," Eggman's voice purred through the speakers. "See how much better he is when he's quiet?"
And Tails hated that he agreed.
Tails' hands came up to grip the bars of his cage, knuckles white, trying to ground himself in something that wasn't the wet heat of Sonic's mouth or the visual of his brother - his older brother - taking his cock like it belonged there.
"I'm-" Tails' voice cracked. "I'm not doing this because I want to-" But his hips rolled forward, pushing deeper, and the lie dissolved on his tongue. Because he did want to. Had wanted to for years in the privacy of his own head, in dreams he woke up from ashamed and hard. And now it was happening and he couldn't stop, couldn't pull back, couldn't do anything except chase the sensation of Sonic's throat working around him.
Sonic's eyes were unfocused, tears streaming down his cheeks as he struggled to breathe around the intrusion. The machine behind him had been worked up into a sinister rhythm, was pushing deeper into him, thick base stretching him like a godsend. Deep, hard thrusts that made his whole body jolt forward, forcing him to take Tails deeper with each impact.
This is Tails. This is my little brother. I raised him. I'm supposed to protect him and I'm - I'm going to cum with him in my mouth. I'm going to fucking cum with him down my throat. I want his cum down in my throat.
But the thought spiraled away as pleasure spiked sharp through his gut. Sonic's curled his tongue in rolling arches against the underside, and Tails realized with horror that Sonic was trying. Trying to make this good. Trying to get Tails off so the machine would stop.
"Don't-" Tails gasped, forgetting the rule. "Don't do that, you don't have to-"
Sonic's eyes flickered up to meet his, glassy and wrecked, and he sucked, the machine rocketing against his prostate hard at the protests. He moaned and slurped around Tails, wondering who would break first.
"Fuck-" Tails' hips jerked hard, burying himself to the hilt. Sonic gagged on his ninth inch, throat convulsing, and the sensation was so overwhelming Tails nearly came right then.
Tails could see Sonic's cock hanging heavy and swollen between his legs, tip flushed dark and dripping. Could see the way his thighs trembled, the way his back arched, in tune with each thrust from the machine. His cock was hard, his hips were pushing back onto the dildo even as he tried to pull away, and his throat kept working around Tails like he was trying to milk him dry.
He's close. God, he's getting off on this. The realization sent heat, affection, love flooding through Tails' entire body.
Sonic was his.
"Sonic- " Tails' voice was wrecked. "Are you - do you like- " He cut himself off before finishing the question, terrified of the answer.
Tails' hips started moving with intent now, shallow thrusts into Sonic's mouth, and he hated himself for it. Hated how good it felt. Hated that he couldn't stop. Hated that somewhere in his fucked-up brain, he'd fantasized about this exact scenario - Sonic on his knees, Sonic's mouth stretched around him, Sonic wanting it.
"Your brother's quite the natural," Eggman's voice cut through the haze, delighted. "Look how well he takes you both. Almost like he was made for it."
"Shut up!" Tails snarled, but the machine responded instantly, fucking Sonic so hard he choked, throat closing around Tails' cock in a way that made stars explode behind his eyelids. And then Sonic was moaning a full stream of moans and white was falling out of his hole to the floor below, legs spasming under the hot load he’d just been gifted by the fleshy, hot cock ramming him onto his brother’s cock.
And he wanted more, wanted it again, wanted to cum on the sensation.
"Careful, fox," Eggman warned, amused that they'd gotten so far as the cream-pie function. "Every outburst makes it worse for him. Unless..." A pause, theatrical and cruel. "Unless you want to make it worse? Maybe you like watching him struggle?" Tails' face burned.
Sonic's eyes were rolling back now, pleasure and panic and oxygen deprivation mixing into something that looked dangerously close to unconscious bliss. There was a puddle forming on the concrete beneath him of his own pre-ejaculate and what he hoped was fake cum. And Tails realized with sick fascination that Sonic might actually cum from this. Might cum untouched with a dildo in his ass and his brother's cock down his throat.
And he couldn’t wait.
"That's it," Tails heard himself murmur, voice dark and foreign. "Just a little more, Sonic. You're doing so good-"
The praise made Sonic whimper. Made his eyes focus just enough to meet Tails' gaze, recognize the desperate, shameful need - made Tails realize he didn't want to give this up, not ever. Everything clicked, why he'd never had an interest in anyone he met, why girls made him so uncomfortable.
The only person he'd ever wanted in his twenty-five years, the only person he'd ever want - was Sonic. No one else could hold a candle.
"You're beautiful like this," Tails whispered, the words slipping out before he could stop them. "I've wanted - God, Sonic, I've wanted this for so long. I love you, I love you, I love you," he cooed.
Sonic's eyes went wide. Shocked. Horrified. Aroused. His throat was working overtime, swallowing around Tails, trying to breathe, trying to process the confession while being fucked from both ends. Trying to cum like a polite hedgehog, a good brother.
Tails brought two finger to his chin, his throat as far as he could reach it, caressed the nerves under, felt the slide of his cock forcing Sonic’s Adam’s Apple to bob around. And he didn’t know what he was doing, he couldn’t focus, he was so hard and felt so strongly that Sonic needed another load to cum.
And that thought made him loose all control over his thrusts, pumping forward in a desperate chase for an orgasm that would damn him for life, felt inevitable, his to experience and his alone.
And it was the drugs - it was just the drugs.
"Gonna cum down your throat," the fox gasped. "Gonna make you swallow every drop. And then - then I'm gonna remember this forever. Remember what you looked like right now. Remember that you're mine-"
Sonic's eyes were streaming now, tears and drool and overwhelm, but his tongue kept working. Kept encouraging. Kept begging for it in ways his voice couldn't.
The machine hit something particularly devastating inside Sonic and his whole body seized. His cock jerked, swelling impossibly harder, and Tails realized with awe that Sonic was about to cum. Blue hips worked like sin, matching his pace on Tails, and the image alone would have been enough to tip the Fox overboard - but the way Sonic was sucking, sucking him deep in a full swallow, suffocating on how engorged Tails was-
"Oh fuck - Sonic - Sonic-"
Tails came first, spilling down Sonic's throat with a broken cry. Hot and thick and claiming, forcing Sonic to swallow it all while the machine continued its relentless assault.
And then - true to Eggman's word - the machine stopped. Stopped right as Sonic was being filled, spilled into, and his body convulsed on nothing - nothing but Tails cock in his mouth.
Sonic whimpered around Tails' cock, throat still working instinctively to swallow Tails down, but the machine that had been driving him toward orgasm was gone. Pulled away right as he reached the edge, leaving him teetering on the brink with nothing to push him over.
No no no please-
But his body didn't care about please. The sensation of Tails pulsing in his throat, the taste of him, the fullness of his mouth combined with the sudden, aching emptiness of his hole - it was enough.
Barely.
Sonic came loud, impossible around Tails' cock - a muffled, desperate sound that vibrated through Tails' entire length. His untouched cock pulsed, painting the concrete white, body convulsing as the most intense, most disappointing orgasm of his life tore through him.
He came around the loss, devastated - wishing Tails was filling him instead, satisfying him fully.
Tails stayed buried in his throat through it, watching Sonic fall apart, his body spasming through release while he clenched around nothing, trying to find the fullness that had just been stolen.
The restraints clicked open.
Sonic collapsed immediately - boneless, wrecked - barely missing the pool of slick and cum and synthetic lubricant spreading across the concrete. His limbs wouldn't hold him. Everything hurt and felt good and felt wrong all at once.
Tails pulled back too, slipping from Sonic's mouth with a wet pop that made them both flinch. Sonic gasped for air, coughing, drool and cum dripping from his chin in a way that was absolutely filthy.
"Sonic- " Tails dropped to his knees, hands hovering uncertainly. Not sure where to touch. Not sure if he was allowed. "Are you - God, are you okay?"
"Don't." Sonic's voice was wrecked, barely recognizable. "Just - don't."
But even as he said it, his body betrayed him - leaning slightly toward Tails' warmth, seeking comfort even as his mind recoiled from the intimacy of what they'd just done. He could still feel it - the absence where the machine had been. The orgasm had taken the edge off but left him feeling empty in a way that was almost worse than the desperation - and he was afraid of that desire getting mixed up in the wrong relationship.
Tails' hands finally landed - one on Sonic's shoulder, gentle and grounding, the other coming up to wipe the mess from his chin with a tenderness that made Sonic want to cry.
"I've got you," Tails murmured, and the words were so familiar Sonic could feel the crash out coming with reality around the corner. "You're okay. I've got you."
He couldn't admit that some sick part of him had been relieved when Tails offered, had wanted his mouth full and his throat working and his little brother's taste on his tongue even as shame screamed at him.
Tails looked down at him - at the mess he was, at the evidence painting his thighs and the concrete, at the way Sonic's hole was still visibly twitching, still seeking.
And Tails felt too many things about that image. Guilt, yes. But also arousal, protectiveness, possession.
"Sonic." His hand came back to Sonic's face, reaching between the bars, thumb brushing away another streak of cum. "Look at me."
Sonic did, found Tails staring at him with an intensity that made his breath catch.
"I need to know," Tails said carefully. "When you came, what were you thinking about?"
"I don't-" Sonic tried to look away but Tails' hand held him steady.
"Please." The word was soft, vulnerable. "I need to know if it was the machine or if it was-" He swallowed hard, his confession hanging off what little was left of his sanity. "If it was me."
Sonic's face burned. Because he didn't know. Couldn’t know. His body had responded and his brain had shut off and somewhere in the middle he'd swallowed Tails' cum and liked it and-
"I-I don't know," he settled on, avoided because avoidance was easier. But one look in Tails eyes said there was hope, a future riding on the answer. "I didn't hate it, though. I couldn't stop thinking about how wrong it was and how good it felt."
Tails made a soft, pained sound.
"I'm fucked up," Sonic continued, words spilling out now. "I'm so fucked up because I liked it, I liked having you in my mouth, I liked the way you looked at me like - like-"
"Like I've wanted you for years?" Tails finished quietly. "Like I've been in love with you since before I knew what love meant?"
The confession hung in the air between them, both of them painted in shame and release and the knowledge that everything had just changed irrevocably.
"Well!" Eggman's voice shattered the moment, gleeful and grating. "That was quite the show! I do believe I have excellent footage for-"
"You're dead," Tails said quietly, voice flat and dangerous in a way Sonic had never heard before. His hand left Sonic's face to reach for something - a tool, a weapon, anything. "The second we get out of here, you're dead."
All Sonic could focus on was the way Tails was looking at him dark and possessive and hungry, like he’d tear the sky down - and realized with startling clarity that this wasn't an ending at all.
Maybe, it was just the beginning.