Everyone knows Derek needs Stiles; that much is obvious. Everyone sees the tiny bit of tension leak out of him when Stiles is near and they know there are things he only tells Stiles and parts of himself no one but Stiles gets to see. Some people don't really get why he puts up with Stiles' shit 24/7 but they accept it as something that works, even though it defies logic.
Derek is walled in, locked up in a box that never opens. When he lets a little vulnerability or emotion show, it's carefully measured and delivered. He's self aware in a way that's both admirable to everyone around him but damaging to himself. It's also safe; and safe is what works. Safe is what keeps him functioning even when shit hits the bottom and he's got nothing left to lose.
It's obvious that he needs Stiles and that Stiles has somehow become his lock-box. Somewhere along the line, when no one was looking, despite all the care he takes to keep himself sealed, he unlocked himself and crawled into Stiles.
He locks his heart up beneath Stiles' sternum and wedges hope under each lung. He takes the things he dreams of when early morning sunlight is filtering through the dilapidated roof and he's hovering in that soft place between sleep and wakefulness, he takes them and then he fits them into Stiles' palms. Derek's goodness is inadvertently spread through Stiles' torso, up into his shoulders and down his arms and to his wrists.
If Derek could take a thermographic image of Stiles’ body he would not be shocked to see Stiles' skin burning bright from inside his bones. It's all hot whites and yellows from his radius and ulna up through his clavicles and all the way down to his lumbar vertebrae. Derek would tell you that Stiles is just bright like that, he's always glowing. Derek has no idea it's all his good he's locked up in Stiles' bones. He doesn't know he has that much good inside of him to press into Stiles' skin.
When Stiles is bursting with his own good and all of Derek’s, and Derek knows Stiles' body as well as his own, he starts to let go of even more. He begins to keep his insecurities at the nape of Stiles’ neck. All the stupid shit he would never admit to worrying over, the things that make him feel weak or vulnerable are carefully placed in the muscle and hair found there. When Stiles reaches back to nervously brush his hand across his neck, Derek's daybreak dreams bleed into his uncertainty and frailties. It should turn the good he keeps in Stiles' palms into bad, but instead Stiles creates something soothing and it turns to bliss. Derek traps his bliss in Stiles' grin.
The guy isn't edgy like he probably thinks he is. He's not cold or gruff. He's warmth. Stiles would tell you that Derek is warmth personified. Talking to Derek feels like laying on the carpet with your feet in the sun. Sharing something secret and vulnerable with him makes Stiles think of the sky; and it's always clear and blue. He has parts of him that haven't been warm in so long. Because he's silly and generally enthusiastic, everyone assumes he's fine. Sometimes he feels so alone that he thinks his bones might split and fall apart. Everything feels stiff and unforgiving. He can feel his body ache and creak like an old house when he tries to function despite the cold and hardness mixed in with his marrow.
Then he hears Derek grumbling and bitching and he can feel the guy scowling at his back. Derek likes to appear aloof and intimidating. He likes to pretend he doesn't have a sense of humor or revel in a big hug or the arm of a loud boy slung over his shoulders. When Stiles hears a growl in response to his jokes, he feels an emanating warmth spread up through his chest. Sometimes it makes his throat tighten and he has to brush at his eyes real quick. It's like having a cat sleep on your lap or a really good home cooked meal inside your belly. There is warmth and then there's the warmth you feel when you arrive home. That slow unwinding and that release of air from your lungs that you didn't realize you were holding the entire time you were out. You're finally lax and your insides feel put back in the right order again. You're home.
Stiles isn't always incognizant to himself. He seems chaotic and clumsy; and his thoughts aren't organized, but he has more clarity than people would assume.
He knows that Derek is just as imperative to him as he is to Derek. Derek is tolerant and fond when Stiles' brain can't seem to make his mouth stop. He tells Stiles to shut up, stop, breathe, and calm the fuck down. Stiles turns it all into a joke like always, but it works. Derek turns off the chaos inside his head and smooths over the things that feel raw or panicky. Derek doesn't know where the bad parts inside himself went. He assumes he held them back when everything else was pressed down and safely placed inside of Stiles. He doesn't know the kid stole it.
Stiles holds the bad at his ankles so when he walks he helps Derek walk a little easier. He holds the bad in his knees so when they bend and flex, the knotted tension in Derek's back will slowly loosen. He locks it up inside his lungs so when he takes a deep breath and exhales, Derek feels a bit lighter and he breathes a little smoother. He flattens it and pushes it under the skin behind his ears so that when Derek brushes his mouth along the spot in an attempt to comfort him, he helps heal his own wounds as well. Derek doesn't know that he glanced away once for just a second and Stiles stole the bad from his lock-box so he could carry it too. Derek isn't sure what's happening to him and he still tells himself (and everyone who will listen) that he prefers to be alone.
There's this boy though, who got him an old couch and damn lamp one time. A seemingly klutzy, obnoxious, uncoordinated guy who touches Derek too much when he's around and smacks his chest with flailing arms when he tells stories. He never actually says much but he talks too much; and Derek should feel embarrassed or irritated or just really pissed off because this kid just doesn't know when to stop and when he does know, he still doesn't stop. He walks around housing Derek's soul like he has a right to, like he has no idea he's home for this man.
It's not about falling in love or being in love. It's something more than that. It's something else. It's an arrow on poorly drawn graph or an entire skeletal system housing a heart. Derek can't make sense of any of it and he spends a lot of time asking himself how the hell this happened. When he yells about it, frowning and pointing an accusing finger, Stiles just shrugs, smirks, and eats another french fry. "I don't know, man but I DO know these need more salt. God, are these even real fries? The thing about french fries..." and Derek listens to the rant and finds himself engaged in a conversation about fried potatoes when just seconds ago he was angry and determined to make this stop or at least put all the pieces together.
When Derek is pretending not to paying attention Stiles brushes fingers along his jawline, takes the tension into his fingertips and Derek smiles. Later he's annoyed with himself because he's in such a goddamn good mood and he can't figure out how this happened. He's being childish but he doesn't care. He wants to mope and he's good at brooding. He's good at guilt and ugly things.
Stiles looks at Derek like he's special and it confuses him. He believes he's hard, mean and unaffected. He wants to be hard, abrasive shell and impenetrable fences. When he asks Stiles why he's fucking staring, Stiles just smiles a little and says, "Sometimes you're so bright it hurts to look but I can't stop”, then he wiggles his fingers and says, “Werewolf magic!” and Derek rolls his eyes, exasperated and more than a little confused. He wants to know if the brightness hurts Stiles’ eyes, or his heart like Stiles hurts his heart, and heals his heart, and none of this makes any sense.
Stiles is a mood killer, turning everything into a joke. In bed, he talks or laughs like he can't contain himself even during sex. Especially during sex. He acts so damn thrilled about a simple blow job or foreplay. He sometimes stops things right when they get good then he leans in and wraps his arms around Derek and hugs him hard. Derek feels a little lost and he wants to tell Stiles he's weird or to just get on with it but instead he finds himself pressing his face into Stiles' neck and nuzzling. He inhales, and something settles around him.
Stiles likes to sit with his hand and fingers resting at the nape of Derek's neck and tell him he's too tense. He says Derek needs to lighten up. Then he scrapes lightly with his fingertips before leaning in to press his open mouth there and nuzzle a little.
Derek isn't really into PDA. He's not very tactile and he prefers affection to be little and far in between. Stiles can't go 10 seconds without accidentally bumping into someone. He touches when he talks, he reaches out to brush arms, he sits too close, he hugs frequently. It should make Derek feel suffocated and scared. It should annoy him and make him feel like Stiles is too clingy or needy. He should tell him to stop.
Sometimes he grumbles and shakes his head but Stiles just teases him and calls him embarrassing pet names in mocking, saccharine tone. Then he laughs as he leans in to rub his face into Derek's arm affectionately before he runs off. Derek sighs. He doesn't tell him to stop. Stiles is the exception and he doesn't understand how. Stiles breaks all of Derek's rules and tears down all of the walls he's carefully constructed. Stiles doesn't really know all of this. He has an idea, but he's a little unaware. Derek doesn't really say much about it unless he's narrowing his eyes at him and asking Stiles how he did this.
Derek doesn't know why things feel lighter, better or somehow more manageable. Stiles doesn't tell him that he stole the bad from him. He doesn't tell him how bright and warm he is. Derek doesn't tell Stiles that he's become home.
Stiles is a thief. His bones house Derek's insides and keep his pieces together. Derek is a sun. He's a clear day and he lights Stiles up from the inside, keeping him warm and lit. Derek tries making a list when he's alone. After it's all down on paper he's left with couches and houses and things that don't make sense like stupid graphs and sunlight. Stiles ends up sneaking up on him and exclaims, “I KNEW IT! You DO write brooding poetry about me.”
Before Derek can shove at him, Stiles bends down and licks his neck. Then runs off laughing and yelling something about demanding sonnets. Derek sighs and gets up to chase after him. He figures some things that don't make sense are okay so long as they seem to fit right.