Chapter Text
Things have been different since the Shatterverse incident.
Sonic's been making a concerted effort to listen to his friends, which has certainly helped during the few fights against they've had Eggman since. It's not like the issues they've faced in the past have been easily avoidable all this time, but, well…
Let's just say there haven't been as many problems lately.
Outside of combat, however, things haven't been going as smoothly as Sonic might have hoped. He's been trying to spend more time with his friends, being more attentive to their wants and needs. That went well for about a week, before those wants and needs shifted to wanting Sonic to shut up and needing some time away from him.
And after Sonic made an effort to talk to Amy about his feelings, too. That's hard enough when he doesn't have to dodge around the minefield that is everything that happened in the Shatterverse.
He knows, logically, that they must notice and appreciate the effort he's been putting in, but it's hard to really believe that when they tell him to leave.
The only person who hasn't pushed him away yet is Tails. The last thing Sonic wants to do is make his little brother feel suffocated, too, but he's been tossing and turning at night since he returned, thinking about the person Tails could have been if they'd never met.
He doesn't want to overdo it, but he still finds himself hanging around Tails' workshop for the fourth day in a row.
Tails is focused on whatever gadget he's working on now, so Sonic takes the opportunity to fix him a sandwich. He deposits it on the table next to Tails' work bench, beside the untouched bowl of chips he left there an hour earlier.
One thing Sonic has noticed these past few days is that Tails doesn't eat much when he's tinkering. He was vaguely aware of that already—and, logically, he knows that Tails can take care of himself just fine, even if it may not always seem like it—but now that he has the image of Nine's thin frame somewhere in the back of his mind, he's a lot less willing to let it be.
Sonic peers over Tails' shoulder, trying to get a sense for what he's working on. Somewhat predictably, watching Tails work for a minute doesn't clear things up much. He'd ask, but he's still trying to be more attentive to his friends' needs. For Tails, that means giving him time to focus on his work without Sonic chattering in the background.
Instead, he tries to find something else to occupy his time. He scans over the shelves that contain Tails' unfinished or scrapped inventions until he finds something interesting—some kind of square device with three prongs sticking out of the top—to fiddle with.
"Sonic." Tails' voice is casual in a very forced way. Sonic immediately sets the cube back down. "While I appreciate you being here for me—"
There it is. Sonic has finally pushed even Tails' tolerance for his presence too far, and now he's being kicked out.
"—this invention could be dangerous if I don't focus on what I'm doing."
Damn. And Sonic had been trying so hard not to be a distraction, too.
He tries for a smile. "What, is it going to explode or something?"
It's happened before. Mostly, if Sonic is remembering correctly, when Tails experiments with new kinds of power sources. But this gadget is so small and unassuming, Sonic can't imagine that will happen.
Tails looks at his invention, then meaningfully at Sonic. Sonic raises his eyebrows and looks at the device as well.
Now that he's paying more attention, the battery does seem to be emitting some kind of strange glow…
"Oh," he says.
"Yeah," Tails says. An apologetic smile appears on his face. "Maybe you can hang out with Amy for a while?"
He could, if Amy hadn't told him in no uncertain terms that she needed some time to herself.
It could be worse. At least Tails is kicking him out for some reason other than being sick of his company.
Sonic doesn't want to make Tails feel guilty for asking him to leave, so instead of telling the truth he shrugs and says, "Maybe."
Still, he doesn't leave immediately. He can't help but worry. If this thing does explode in Tails' face, shouldn't Sonic be there to ensure he doesn't get hurt? He's fast enough to outrun an explosion, but Tails isn't.
Tails is looking at him expectantly, though, so Sonic rocks back on his heels and plasters a smile on his face. "Well," he does his best to sound cheerful, "see ya later then, bud." He throws out a wink for good measure before racing of.
It's not like Sonic can't entertain himself just fine. If none of his friends want to see him right now, he'll just go for a run. With all the time he spent around his team recently, he hasn't really had a chance to cut loose.
Yeah. Sonic will be just fine on his own.
He's been running for only a few minutes when Shadow pops into existence in front of him. Sonic stops abruptly, skidding to a complete halt a few feet in front of the other hedgehog instead of crashing into him as he'd half feared would happen.
"Shadow," he says, more surprised than annoyed by the dark hedgehog's sudden appearance, "What are you—"
"The fox needs to be stopped," Shadow growls, arms crossed over his chest.
Sonic stiffens, looking over his shoulder as if he can somehow see Tails' workshop from halfway across the island. Although, if it exploded, Sonic supposes he probably would be able to see it.
When no immediate problems become apparent, he turns his attention back to Shadow. He crosses his arms, mirroring Shadow's stance. "What are you talking about?"
"He's creating something dangerous." Shadow's near-perpetual scowl deepens further. "Again."
"Again? When has Tails ever made something dangerous?"
Shadow levels him with a stare.
…Jeez. And here Sonic thought he was having trouble getting over what happened.
Sonic rubs a hand down his face. "You know Tails isn't Nine, right?" The irony of that statement isn't lost on him—nor is it lost on Shadow, who raises an eyebrow, thoroughly unimpressed.
"Yeah, yeah," Sonic flaps his hand dismissively, "I'm one to talk, I know. Doesn't change that I'm right. Besides," he smiles slyly, and doesn't miss the way it makes Shadow tense, "aren't you always telling me you have more important things to do than checking up on us? How do you even know what Tails is up to?"
Shadow growls wordlessly, turning away. Sonic bounds over so he's in front of him again, clasping his hands behind his back and leaning forward. "Oh? Don't tell me you care, all of a sudden?"
Before Sonic can react, Shadow reaches out to push against his face, taking advantage of his lean to easily knock him to the ground. "I care about that reckless fool ending the universe."
Sonic spins from his position on the ground, attempting to sweep Shadow's legs out from under him. Predictably, it doesn't work, but it leaves Shadow open to Sonic's tackle.
He backs off once Shadow hits the ground, point made. "Don't talk about my friends like that."
Instead of getting up normally, Shadow kicks up off the ground like the show-off he is. "Then maybe your friend shouldn't be one invention away from ending the universe." Shadow always says friend like it's a dirty word. As usual, the sound puts a sour taste in Sonic's mouth.
"Will you get off that?" He pokes Shadow in the chest. "Tails hasn't done anything. Even Nine realized what he was doing was wrong in the end."
Shadow glares at the finger in his chest fur like he's trying to explode it with his mind. Sonic retracts his hand before Shadow can remember that, while he may not possess deadly eye-lasers, there are plenty of other ways for him to cause Sonic grievous bodily harm.
"Just leave Tails alone, man. He's not gonna hurt anybody."
Shadow gives him an unreadable look. "We'll see."
"What's that—" Shadow teleports away in the middle of the sentence. "—supposed to mean? Ugh. Rude!" Sonic yells at the air, just in case Shadow is still somewhere nearby. "You could at least let me finish!"
It's not like Sonic doesn't understand where he's coming from; even he is having trouble putting everything that happened behind him. Since Shadow has always been paranoid, it must be even harder for him. But he also knows Shadow has a tendency to overreact to perceived threats. If he thinks for even a moment that Tails is going to cause trouble…
Shit. Sonic is going to have to keep an eye on him.
Over the next few days, Sonic keeps tabs on Tails from a distance, checking up on him every so often. He quickly starts to notice a pattern. Wherever Tails is, Shadow can be found lurking behind the nearest available cover. He vanishes whenever Sonic gets too close—meaning Sonic can't even properly confront him—but he's always there again the next time Sonic checks on Tails.
Thankfully, Tails seems blissfully unaware of his newly acquired, well, shadow, but Sonic doesn't know how much longer this can continue before Tails does something that gives Shadow the wrong impression and ends up in serious danger.
So, he goes with the first plan he can think of to draw Shadow out into the open and invites his friends to a picnic. Amy and Knuckles agree readily enough; it seems the few days Sonic spent on his own were enough for them to want to hang out with him again.
He scans the area for Shadow as he approaches Tails' workshop, raising an eyebrow in his direction when he notices him perched in a tree on a nearby hill. Shadow doesn't run off—he usually only does that when Sonic tries to approach—but he does scowl deeply.
Whatever. When is Shadow not scowling?
Sonic knocks on the door to Tails' workshop, rocking back and forth on his feet as he waits for the fox.
"Up for a picnic?" He asks when Tails comes to the door. He lifts the basket, hoping that the promise of food will be enough incentive for Tails to finally trade in his precious tools for some much-needed company. "I invited Amy and Knux as well. They should be waiting for us on the beach. Who knows, maybe Rouge will even show up."
He did invite her, but he received no reply. Not surprising—by now he's well aware the bat is only reachable when she wants to be.
Tails looks over his shoulder, clearly hesitant. "Now's not a great time."
Sonic stands on his toes to look over Tails into his workshop, trying to see what he's working on. It kind of looks like the same gadget he was tinkering with before. "Is that still the…" Damn, he doesn't actually know what Tails was making. "…the doodad you were working on when I was here?"
Tails bites his lip, a clear admission of guilt.
"Jeez, bud. If you're banging your head against it this much, isn't it better to take a break? Get your mind off it for a bit, so you can come at it with fresh eyes later?" He waggles the picnic basket. "Besides, I bet you're pretty hungry."
As if on cue, Tails' stomach growls. Sonic feels his smile widen.
Tails fidgets for a moment before his shoulders relax just a fraction. "Alright, I'll come. Just let me put the shield generator away so it doesn't blow up while I'm gone."
He heads back inside. Sonic leans back so he can make eye contact with Shadow, smiling smugly. He's being careful, see? No murder needed.
From this far away he can't hear Shadow respond, but he can imagine his annoyed growl just fine.
They maintain eye contact until, without warning, Shadow abruptly teleports away.
"I'm ready."
Sonic jumps at Tails sudden appearance. The fox laughs at that, and Sonic feels his mouth pull into a fond smile.
"C'mon," he slings his free arm around Tails' shoulders, "let's go meet up with the others."
During the picnic, Sonic divides his attention between making sure Tails eats enough and keeping an eye out for Shadow. He's not sure if Shadow will show up when there's this many people in such an open area—but if he does, Sonic will be ready.
Shadow doesn't make an appearance the entire time they're eating, so Sonic figures it's probably safe to play a game of volleyball. He's proven wrong when he glances over to see the dark hedgehog crouched at the edge of the cliff above where Tails and Amy are sitting.
Before he can think about what he's doing, Sonic has tackled the other hedgehog to the ground. They roll some distance, trying to hit each other with elbows and knees before their momentum bring them to a stop. Sonic recovers first, managing to jab Shadow in the throat before racing off again, in the opposite direction of where his friends should still be sitting. With any luck, Shadow will follow him, instead of doing… whatever he was planning on doing to Tails.
Shadow does chase him, but Sonic doesn't feel especially lucky when he gets thrown into the face of a cliff with significant force. Shadow doesn't give him a single moment to recover, fist impacting the compacted dirt not even a second later, hard enough to send dust and debris flying—right where Sonic's face would have been if he hadn't dodged in time.
Sonic scrambles out of the way of a kick aimed at his ribs, and retaliates with a punch to Shadow's jaw—except Shadow dodges, so it ends up glancing off his shoulder instead.
They trade blows like that for a while; Sonic even manages to get a few solid hits in, including a kick to the side of Shadow's knee that actually buys him a second to breathe. He regrets that maneuver soon enough, since all it seems to have accomplished is to make Shadow fight with more ferocity.
It doesn't take long after that for Shadow to pin him against another cliff face by the shoulders. He's too close to wind up for a good kick, so Sonic does the only thing he can think of and headbutts him.
Another opponent would probably have staggered back from that, but Shadow only snarls and shifts his grip to Sonic's throat so he can't do it again. It leaves Sonic's arms free, but he can't get his punches up to speed like this. He suspects Shadow would be more bothered by a mosquito than he is by Sonic's attempts to hit him.
"What the hell is your problem?" He demands, once he's accepted the futility of continuing to fight.
Slowly and deliberately, Shadow wipes some blood from a fresh cut on his lip with the hand not currently restraining the other hedgehog. "Funny." He gazes at his now bloodstained glove before looking Sonic in the eye. "Shouldn't that be my line?"
Sonic lifts his head. They've hurt each other much worse before; he's not going to feel guilty over a measly little split lip.
Unfortunately, Shadow takes advantage of the movement to tighten his grip on Sonic's neck. It's not tight enough to cut off his airflow, but it's definitely a little harder to breathe.
"You were going to hurt Tails," Sonic wheezes.
"I was getting rid of a problem," Shadow argues.
"Bullshit," Sonic spits, "Tails would never hurt anybody, and you know it."
"I don't know anything…" Shadow trails off. In spite of the position he's in, Sonic smirks.
"I'd say that's—geh." His quip gets abruptly cut off when Shadow tightens his grip even more, cutting off Sonic's oxygen supply entirely for a brief moment before releasing him. Sonic slumps forwards, coughing and rubbing at his sore throat. He'll probably be feeling that for a while.
Shadow takes advantage of Sonic being bent over to loom over him. "You trusted that other fox, too. Remind me—how did that turn out?"
Sonic glares up at him. "It's different. I've known Tails for years. He's not just suddenly going to…" An image of Nine swims before his eyes; the moment after he shouted he was real, when Sonic could see all the hurt laid bare on his face. He shakes his head to clear it. "…turn evil, or whatever."
"You don't seem too sure of that."
"Well," Sonic straightens up, ignoring a painful twinge in his back. Shadow must have thrown him harder than he realized. "I am. So you'd better leave Tails alone."
Shadow crosses his arms over his chest. "Or what?"
"Or I'll stop you," Sonic raises his head again, looking down his nose at his rival, "No matter what it takes."
For a moment, Shadow just stares. Then his lips draw into a smirk. "I can take you."
Inwardly, Sonic groans; he doesn't want to fight again when he's already hurt. He doesn't let any of that show, though, sliding his feet into a fighting stance and balling his hands into fists. "Yeah? Prove it."
Shadow growls, getting ready for the fight to continue as well—before his ears twitch, and he straightens back up. "Some other time. It seems your friends have finally caught up."
Sonic realizes what's happening just a fraction of a second to late. He lunges forward, trying to grab Shadow to keep him from leaving, but his hands close around empty air.
He falls to his knees, as much from overbalancing after trying to grab Shadow as from frustration. "Damn it." He punches the ground in an attempt to let out some of his emotions, but all it accomplishes is making his hand hurt.
"Sonic!"
Just as Shadow said, his friends have arrived. Sonic looks up to see them running towards him. Amy is the first to reach him, dropping to her knees by his side.
"Sonic! Are you okay? What happened? Did Eggman attack?" She gasps. "You're bleeding!"
…He is? "I am?"
She tilts his head up gently, wiping a thumb below his nose with equal care. Sure enough, her glove comes away stained with blood.
"Oh." He thinks back over the fight, trying to remember if he caught any punches with his face.
"Are you hurt anywhere else?" She asks.
Slowly, so as not to aggravate his aching neck, Sonic shakes his head. "No." He tries to stand up, only for his back to twinge again. Something must have shown on his face, because Amy makes a distressed noise and grabs his hand. "Okay, I'm a little hurt, but it's nothing serious." He gives her hand a squeeze he hopes is reassuring. "Promise."
"What happened?" Tails asks. "You just ran off by yourself without saying anything."
"We were worried," Amy adds. Tails nods his agreement. They both look at Knuckles, who shrugs.
"Sonic can handle himself."
Sonic smiles, becoming aware of a bruise on his jaw when the motion makes the skin pull uncomfortably. "Thanks, man."
"That's not the point," Amy says. Sonic shrinks in on himself a little at her stern tone. "We're a team. You shouldn't go running into danger alone."
Sonic's shoulders slump. He's been making an effort to be better at the whole teamwork thing, but this… It's not something he wants the others involved in. They shouldn't need to concern themselves with what happened in the Shatterverse, or Shadow's paranoid reaction to it.
With a sigh, he runs a hand through his quills, shaking loose a bunch of dirt and dust. Man, did Shadow have some kind of grudge against that cliff he threw him against? It feels like half the cliff face is stuck in his quills.
Hopefully Tails will let him borrow his shower later.
"I know," he says, "Really. But this is…" Private. Somehow he doesn't think anybody will accept that answer, so the word rolls around in his mouth unsaid.
"Does it have something to do with what happened when we fought Eggman for the Paradox Prism?"
Sonic whips his head around to look at Tails, mouth open in shock—and instantly regrets it. Seriously, ow. His vision blacks out for a moment. When it clears, he's on his knees again, one hand pressed against his neck and the other clutching Amy's arm.
Amy looks at him with concern before turning a steely gaze towards Tails. "Is now really the time? Sonic's hurt. He needs to lie down."
There's a moment of silence before Tails says, "Fine. I'll go on ahead and get the couch ready."
Amy huffs, probably pleased to have stared Tails into submission. "Thank you. Knuckles, you carry Sonic. Make sure to support his head properly so his neck doesn't get hurt further."
"Support my head?" Sonic parrots. "I'm not a baby, Amy. I can support my own head just fine."
Even so, he lets Knuckles pick him up and maneuver him into a comfortable position—head resting against Knuckles shoulder, neck supported by a bicep—without further complaint.
Sonic is deposited on Tails' couch with the appropriate amount of fanfare for such a recurring event—that is to say, little to none. Amy stays long enough to make sure the two pillows he's leaning against are properly fluffed and that there's a second ice pack in the freezer for when this one warms up before she heads out.
"Want me to stick around?" Knuckles asks. "Just so you have some backup, if you need it."
Sonic starts to shake his head, but thinks better of it before he can hurt himself again. "No need. But thank you."
After a moment, Knuckles shrugs. "If you say so. Later, dude."
Sonic raises his hand in a wave. "Later."
Tails sees Knuckles out before dragging a chair over so they can look at each other while he sits in it.
"Are you sure you're alright?"
"Yeah, bud. Just a little banged up," Sonic attempts a reassuring smile, "I'll be fine tomorrow."
Tails leans his elbows on his knees, staring intently at Sonic's face. "Were you fighting Shadow?"
Sonic fights the instinct to tense up. He should have expected Tails to figure that much out. Besides, it's not like he's trying to hide it, exactly… Just why they were fighting. "Yeah," he admits, "I was fighting Shadow."
Tails is silent for a long moment. When he speaks again, his voice is soft. "Because he's been… stalking me, or whatever?"
Damn it. Sonic closes his eyes with a sigh. Sometimes he wishes Tails was just a little less intelligent. Or at least less observant.
"What's going on with you two?" Tails asks. "You've both been weird ever since…"
The Paradox Prism. Sonic probably should have expected that Tails would realize something happened. After all, to his friends his changes in behavior must seem to have come out of nowhere. He was just hoping the fact that they were positive changes would keep them from being suspicious. No such luck, apparently.
Then again, he might have been able to brush it off if Tails hadn't noticed Shadow following him around. Isn't Shadow supposed to be good at that kind of thing? Sonic is definitely going to rub this in his face the next time he sees him.
"Shadow…" He pauses, trying to think of what to say that won't make Tails ask even more questions he doesn't want to answer. "He's got it in his head that you're making something dangerous."
Tails' eyebrows rise in surprise. "What? Why?"
Sonic shrugs, wincing a little when the movement draws attention to the bruises on his neck. The ice is helping, though; it already hurts significantly less than it did even ten minutes ago. "Dunno."
It's not… exactly a lie. He knows why Shadow is more likely to be suspicious of Tails, but he doesn't know what exactly convinced him he's doing something dangerous now.
Tails looks at him. Sonic squirms uncomfortably under his gaze.
"Look," he says, "I don't think Shadow will actually do anything. Eventually he'll realize you're harmless and back off." Or I'll make him.
Tails hunches his shoulders forward, biting his lip. "But…"
"I'm serious," Sonic says. He sits up a little, careful not to aggravate his back, so he can look Tails in the eye properly. "I won't let anything happen to you. But," he tacks on, when Tails doesn't look convinced, "if you're worried, maybe lay off the inventions entirely for a little bit."
Tails makes a face like he just watched Sonic punt a dozen puppies into the sun.
"Or, you know," Sonic hurries to say, "just stick to the obviously harmless stuff."
"The shield generator is obviously harmless," Tails mutters. "It's a shield. That's the whole point."
Sonic wants to throw his hands up, but he settles for rolling his eyes instead. "Then maybe don't go around calling things you're working on dangerous where Shadow can hear."
Tails stares at him, thoroughly unimpressed. "He has super hearing."
Sonic huffs. Yeah, so don't say anything stupid. "Fine. Then," he settles back into the couch, "explain what's so dangerous about this shield generator of yours. Or, actually, what's not dangerous about it. Just in case Mr. Super Hearing is listening."
Tails gives him a flat look. "If you want to take a nap, you can just say so."
Busted. Seems like Tails has caught on to Sonic using his technobabble as a bedtime story. He grins. "Who says your explanation can't serve multiple purposes?"
Tails looks at the ceiling with a long-suffering sigh. Even though Sonic knows he's probably—hopefully—just playing up the annoyance, it makes him look so much like Nine for a moment that Sonic feels his heart clench.
"If you insist." Tails is smiling gently, looking exactly like—himself. Sonic relaxes into the pillows, getting comfortable.
Tails launches into an explanation of his newest invention. It doesn't take long for Sonic to start drifting off, the sound of his little brother's voice lulling him to sleep.
He wakes up some time later, groggy and disorientated. The familiar surroundings help ground him—he's spent more than a few nights on Tails' couch—and the events of the day come back to him. He moves his neck, relieved to find it only a little sore. When he stands, his back doesn't hurt either.
Sonic stretches, pleased that his various injuries have dulled to mere background aches.
That means it's time for his second order of business—washing what seems to be an entire beach worth of dirt out of his quills.
Light shines through the crack under the door to Tails' workshop. Sonic stumbles over, feet still clumsy from sleep, and throws it open without bothering to knock. Tails is standing near the open window, some kind of knife held in a white-knuckled grip.
"Tails? What's going on?"
It's like a switch has been flipped. Tails instantly relaxes, his hold on the knife easing up. "Nothing," he says. He turns away from the window so he can look at Sonic properly. "What's up? Need something?"
Weird. Sonic stares, searching for any sign that Tails is lying, but his body language doesn't betray anything—and besides, Tails wouldn't lie to him.
"A shower would be nice," he says. A clump of dirt falls from his quills to the floor, and he winces in tandem with the fox. "And maybe something to clean the bathroom with, after?"
Tails sighs, rubbing a hand down his face. He glances at the window with an expression Sonic can't quite decipher before saying, "Okay. Give me a second to put everything away."
Sonic waits as patiently as he can as Tails moves the glowing crystal from his workbench to a cabinet with painstaking slowness, tapping an upbeat rhythm on the floor with his foot.
Once the crystal and knife are stashed securely away, Tails retrieves an oil-stained towel from another cabinet. "Here," he holds it out, "You can cover your quills with this on the way to the bathroom."
Sonic looks at it distastefully. "It's dirty."
"So are you," Tails points out, "My floor, however, is clean. And I'd prefer to keep it that way."
Sonic scrunches up his nose, but accepts the towel anyway. He presses it against his back best as he can, struggling to hold it there until Tails says, "Gimme. I'll hold the bottom, if you can keep the top in place."
They shuffle upstairs to the bathroom like that. It's a little awkward, but they make it work—and at least Sonic doesn't hear any more clumps of dirt hit the ground.
When they arrive, Tails gingerly removes the towel, shaking the dirt that's collected there into the trash.
"Thanks, man. I'll just—"
"Nuh uh," Tails interrupts him, "I'm not about to let you clog my drain." He lays the towel on the floor. "Sit."
Sonic grumbles, but takes a seat on the towel. Tails bustles around for a second, then sits down behind him, wasting no time before attacking his quills with a steel comb.
A minute passes in silence. This isn't the first time Tails has had to brush something out of Sonic's quills, but it's not a regular enough occurrence for him to feel entirely comfortable with the ministrations.
"You don't have to do this, you know," Sonic says eventually.
"So I should just let you ruin my bathroom instead?"
Something twists in Sonic's gut. He's been working so hard on being less selfish since he nearly destroyed the universe—but here he is, making Tails do things for him again.
"Besides, I don't mind," Tails adds, "A little grooming is nice every now and then."
Sonic makes a conscious effort to relax. "Want me to do you next?"
Tails hums. "If you want."
Before Sonic can respond, Tails yanks the comb through his quills with particular force. Sonic yelps in pain.
"Sorry," Tails says. When goes back to combing, it's as gentle as before. "If you do want to, we should wait until after you've showered. The longer you leave this stuff in here, the harder it'll be to get out."
"I guess," Sonic says. He was half-joking, before, but now that he's brought it up the idea has taken root.
Growing up an orphan hasn't given him a lot of experience with social grooming. But he has to admit, the more Tails teases the dirt from between his quills, the more enjoyable he finds it. It could be kind of nice to return the favor.
He waits until Tails announces he's finished to say, "I think I'd like to."
"Hm?" Tails doesn't even look up from where he's throwing the new batch of dirt in the trash can.
"Brush you," Sonic clarifies, trying not to sound as awkward as he feels, "Once I'm done showering. If you want me to, I mean."
Tails balls up the towel and turns around, a smile on his face. "Sure! Not with this comb, though. That might work for your quills, but my fur's not as sturdy."
Warmth blossoms in Sonic's chest at the thought that Tails has a comb just for him. "Okay."
"Okay." Tails lifts the dirty towel. "I'm gonna throw this in the wash and put some clean covers on your sheets. You know where everything is?"
"Yeah." This is hardly the first time Sonic has borrowed Tails' shower. Unless the fox recently decided to rearrange everything, he'll find things just fine. "I'm good. Go do your thing."
Tails leaves, and Sonic takes his time showering, scrubbing himself until the last remnants of dirt have washed out and the warm water has soothed his remaining aches and pains into nothing but a memory. While he certainly loves the freedom that comes with not being tied down to any one place, he has to admit living in a house has certain benefits.
When he returns downstairs, the couch is indeed made up with clean sheet covers. Tails is sitting on it, throwing a soft-looking brush from one hand to the other. He nearly drops it when Sonic comes in, obviously a little startled by his appearance. "Do you still want to…"
"'Course. It was kind of nice when you did it for me so," he shrugs, "I figure it's only polite to return the favor."
Getting to spend time with his brother like this is an arguably even bigger perk of being in Tails' house than the bathroom.
While Tails has had to comb gunk out of Sonic's quills before, this is the first time he's brushing the fox. He probably should have done it when Tails was growing up, but at the time he was still young and stupid himself—not to mention that he didn't exactly have any experience with casual grooming of his own. So he's a little hesitant at first, not quite sure how to go about it, but soon enough Tails starts humming contentedly, continuing until Sonic notices his breathing evening out and his posture relaxing.
"Wanna sleep?" He asks.
Tails nods, so Sonic scoots over to make room. They have to press together to both fit on the narrow couch, but Sonic finds he doesn't mind the contact. While he certainly likes his space most of the time, he also likes being secure in the knowledge that he can keep Tails safe if Shadow tries something again.
He's especially grateful when nightmares of robotic versions of his friends and the screaming of a nine-tailed fox startle him awake some hours later that he can look at the peaceful sleeping face of his little brother and know he didn't have to grow up alone, because Sonic was there for him.
If Sonic has his way, that will never change.