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Tails never thought he would be replaced.
A year or so ago, when he met Sonic, he knew immediately that they were meant to find each other. It was like a puzzle piece fitting into place — like turning the lock in the front door of your new home. Tails had never belonged, but suddenly, he was a sidekick, a best friend. That was everything to him. He never wanted to lose it.
At that time, Sonic didn’t talk with his voice. When communicating with other people, he would rely on exaggerated gestures and facial expressions, and even simple sign language, but he could only get so far. With Tails, it was so easy. Tails understood everything. Sonic could lift one finger, or wink one eye, and Tails would know.
Sonic had a special sign that he did for Tails, and only Tails. He would hover his paw right above the kit’s head, sort of like he was saying You’re short! Tails loved it when Sonic called him little. He never felt embarrassed or belittled. That was his special sign, and to him, it was a huge honor.
Eventually, Sonic began to use his voice. It was sudden — he spoke up while they were eating one day, startling poor Tails so badly he spilled his breakfast all over his lap.
The kit was delighted to hear his idol’s voice. His favorite thing was that Sonic replaced the “little” gesture with a real-life nickname. Little Buddy, he called him. Tails found himself whispering the name all the time, feeling it on his tongue, turning it in his mind. Little Buddy. It was his. His nickname! He’d never had one before, and there was no better feeling in the world than when he was called by it.
Talking out loud took a little practice and a little getting used to. Sonic forgot words occasionally. He had trouble with the more difficult sounds, like “th,” and his L’s and R’s tended to get a little mixed up. But Tails always understood him. That was how it had always been, and how it always would be. It was so special. Just the two of them. Tails and Sonic, Sonic and Tails.
Until it wasn’t. Until they met Knuckles. Things aren’t the same anymore.
Tails doesn’t have anything against the echidna personally. In fact, he kind of likes that air of mysteriousness he carries around him. He’s not easily read, and Tails loves puzzles.
But he can’t help but hold a certain resentment against him. Because Sonic likes Knuckles. Really likes him. Tails thinks Sonic likes Knuckles as much as him. And stealing his hero, his sidekick, his big brother from him: that is unforgivable.
They’ve just knocked Robotnik into the sky again. Tails is giggling, giddy, and Sonic’s laughing, and Knuckles is even smirking a little. It’s good to feel accomplished. Tails feels like doing somersaults in the air.
“Great job, Tails! You’ve gotten so strong!” Sonic gives him a big hug, then he turns to Knuckles and holds up his paw for a high five. “And you too, buddy! That was awesome!”
Tails freezes. He feels his feet touch the ground. His eyes go wide and lock on his brother, watching the way Sonic’s cheeks redden as Knuckles awkwardly returns his high five. Sonic stares at him like he’s holding the world on his shoulders. Like he’s the one who makes the sun shine in the sky.
Tears prick the corners of Tails’s eyes. As dramatic as it is, he feels like the world is crashing down around him. How could Sonic betray him like that?
After a few seconds, Sonic seems to notice Tails’s sudden silence and stillness. He turns to look at him — finally tears his eyes away from Knuckles. “Tails?” he says, sounding worried. “Are you okay?”
Tails feels his lib wobble pathetically. With one last sad look at Sonic, he turns on his heel and stomps off.
He finds a rock to sit behind and plops down on the ground. Pulling his tails into his lap, he hugs them against his chest and rests his chin in the fluffy fur. He sniffles, and a few stray tears roll down his cheeks.
A few moments later, he hears footsteps. He turns away from the sound, tucking his muzzle into his tails. But he knows he can’t hide from his older brother.
Sonic comes around the rock. “Hey,” he says quietly. “Can I sit by you?”
Tails shrugs.
Sonic sinks into the grass beside him and leans against the rock. “What’s wrong?” he asks. “Why’d you go off and hide like that? Did I hurt your feelings?”
Tails pulls his face out of his fur and wipes his eyes. He nods.
“I’m really sorry. What’d I do?” Sonic leans forward, trying to look the fox in the eye.
Tails heaves in a little sigh and reluctantly meets his gaze. Still, he doesn’t answer the question.
“Come on, dude. Please tell me.” Sonic makes puppy dog eyes at him. “I don’t wanna hurt you. Tell me what I did wrong?”
Tails swallows and reaches out, dragging his fingertip through the dirt. “Why did you call Knuckles buddy?” he mumbles.
Sonic blinks. “W-What?” he says, sounding very confused, as if he didn’t hear correctly.
“You always call me buddy. That’s supposed to be my name. Not his.” His gloved claws dig sharply into the soil.
Sonic thinks for a moment. “But I call you Little Buddy,” he says, grinning hopefully. “And I just called Knuckles buddy. It’s totally different! You get it, right?”
“No,” Tails pouts.
“Oh.” Sonic pulls his knees up and gets comfy, settling in for a long brother-to-brother talk. “Well, I think I know why you’re upset. You’re scared I’m going to let Knuckles replace you, right?”
Tails shrugs, refusing to meet his eyes.
“Listen, Tails. First and, uh, foremost. The way I feel about you and the way I feel about Knuckles is totally different.” Sonic smiles, a bit shyly.
Tails swipes his arm beneath his nose. “What does that mean?”
“Uh…” Sonic waves his paw dismissively. “I don’t know the word for it. There probably is one. But, it’s, um. I like you, and I like Knuckles. But it’s a different kind of like.”
“What kind?”
“See, for you, you’re like family to me. I love you because you’re my sidekick and my best friend. But, more than a friend? You’re… You’re a brother.” Sonic gestures with his paws as he works through it. “And Knuckles is. He’s also a friend, but a different type, because I feel closer to you. But also, with Knuckles, there’s something else. He makes me feel like…”
Tails waits while Sonic thinks.
He gives a small whine of frustration. “I don’t know how to say it,” he admits, looking at Tails. “The word. I don’t know it.”
“Well, I can help. What’s it like?” Tails shuffles a little closer.
“It’s hot, and scary, but also… it’s also really…”
Sonic is quiet for a few moments. He smiles eventually, sucking on his bottom lip. “There’s, actually, there’s a lot I could say about him. But let’s talk about that another time. This isn’t the important part. We’re not talking about Knuckles. We’re talking about you, Tails.” He turns to fully face the fox. “I want to make sure you know how important you are to me.”
Tails looks down, a little guilty. “I mean, I do know. I’m just being jealous for no reason.”
Sonic shakes his head. “No, I understand it. You mean a lot to me and I’d feel really hurt if the tables were turned. I don’t think I’ve been the best friend lately. I want to clear things up now.”
He reaches out and takes Tails’s paws into his own, getting the kit’s full attention.
“You always come first,” Sonic begins. “Before anyone or anything else. Nothing could ever replace you. You are your very own category. Knuckles is my friend, but he’ll never fill the same… uh, role that you do.”
“Really?”
“Yeah. Really. I promise, promise, promise.”
Tails’s heart squeezes a little.
“You’re my specialest buddy,” Sonic continues. “My first buddy. Others will come and go, but now that you came, I know you’re never gonna go.”
“Never ever,” Tails agrees with a small smile.
Sonic gives a relieved smile back. “I have an idea. Let’s make a…”
Tails waits for him to find what he’s looking for, but he trails off for a long time before he sighs and looks at his little guy for help. “What’s the word? It’s, like, an agreement that you don’t break. Like a promise, kind of. We’re going to shake on it. There’s a special word.”
“Um—“ Tails thinks for a moment. “A pact?”
Sonic’s eyes light up. “Yes! You are so smart! Let’s make a pact. Right here, right now. You ready?”
Tails nods. Sonic tightens his hold on his paws.
“Okay,” he says, settling in. “I think you’re usually supposed to write this down, but we’re just going to say it. Here we go.” He looks the kit right in the eyes. “Tails, I promise that for the rest of my life I will never forget you, never replace you. You will always be my number one. Best friends forever and ever, and so on. I will be your big brother and you will be my little brother and we’re always gonna stay that way. No matter how many Knuckles’s we meet—“
Tails giggles.
“—and no matter how many badniks we fight, and no matter how much fur you shed on me, and no matter how many quills I get stuck in the Tornado… we’ll always love each other and take care of each other. No matter what.” He nods for emphasis. “Your turn, little buddy.”
Tails swallows. “Sonic,” he begins, and his throat is already getting tight. “Sonic, I promise—“
His voice is cracking, and the hedgehog looks at him very worriedly. Tails quickly shakes his head, reassuring.
“Sonic,” he tries again, “I promise to always take care of you too. Even when you think you don’t need it. I want to be by your side every single minute. When you’re hurt or sick or tired, I’ll help you hold your head up. And if I need you, I know you’ll be ready to have my back too.”
“Of course,” Sonic whispers.
“So let’s not let anything get between us. Because I really—“ Tears spring back into Tails’s eyes, and he lets them, smiling through them. “—really, really, really, really love you. The end.”
“Pinky promise?” Sonic smiles, wide enough to show off the gap from his most recent missing baby tooth.
He holds out his pinky finger, and Tails hooks it with his own. They shake once, twice, three times for good measure. Sonic offers his arms out for a hug, and Tails falls into it with no hesitation.
They rejoin Knuckles, and then they’re all running off again, ready for a new quest. Tails doesn’t feel the ground shaking anymore, even when Sonic meets eyes with the echidna and starts going all giggly. He even smiles at their awkward little display. He has nothing to worry about. He realizes it all now, and wonders how he didn’t see it before.
It can still be Tails and Sonic, Sonic and Tails. And it will be. Everyone knows you don’t break a pinky promise.
With their pact resting safely in the back of his mind, Tails follows his friends towards whatever adventure faces them next.