A/N: This idea has been floating around in my head for months, but since it's Stydia month, I figured I'd get off my ass and write it. Sorry if it sucks; I just really needed to get it out.

Warnings for: mild language, soulmates AU and all associated cliches, Stiles/Lydia, mildly implied sexual content, background canon pairings.

Title comes from "Froot" by Marina and the Diamonds.

Lydia's Mark is unique, as Marks go. Well, technically, every Mark is unique – but the overwhelming majority of them follow a pattern. "Hi, I'm Betty" will appear on someone's left forearm moments after they're born. Somewhere, maybe in the next hospital crib over or maybe in the middle of a Siberian village, someone probably has "nice to meet you, Betty" on the bottom of their right foot or something. Most Marks are just mundane phrases, because after all, most meetings are mundane. You bump into somebody at the grocery store, apologize, and go on your way. It's only later, if you get to know somebody, that they really become special to you.

At least, that's what Lydia's grandmother tells her as she helps her towel off her hair after bath time. Lydia is old enough to remember the conversation later, but only in fragments, as vague as the scent of Johnson's No More Tears shampoo and the color of her grandmother's eyes. "Your Mark is precious, Ariel," her grandmother says. "You'll know as soon as you meet your soul mate."

Lydia's Mark is on the inside of her right thigh – a question in tiny, neat print. "Can I borrow your peach crayon?" Sometimes, when she's a very little girl, she wonders where in the world her answer resides. Not everybody meets their soulmate, but a girl can dream.

That is, of course, until her parents get divorced. Lydia's mother's Mark – "Hold the elevator, please!" on the palm of her right hand – fades until it becomes nothing but a scar, hardly noticeable if it weren't for all the pain it caused. Lydia's never seen her father's Mark – it's possible that it's somewhere not fit for her eyes – but she can only imagine that it fades away, too.

It's one thing for people who aren't soulmates to get married and then divorce. You don't have to be soulmates to love each other, after all. But for her parents to be soulmates and still fall out of love? That's all it takes to prove to Lydia, the most intelligent student at Beacon Hills Elementary School, that love doesn't really exist. Or if it does, it's far too fragile. It's not worth having a soulmate if it doesn't get you anywhere, and Lydia is very concerned with getting somewhere.

She starts third grade in August (her father had left their house for the last time in June.) The pain is still fresh, and when Ms. Jones tells the class she wants a whole sheet of paper about them, including a hand-drawn picture of their family, Lydia draws him in the picture anyway. She's coloring in her mother's skin with the peach crayon when a warm hand taps her on the shoulder.

"Can I borrow your peach crayon?" the boy says.

Lydia's in a bit of a mood, so without even thinking, she snaps, "No."

It's only as he's walking away, looking confused, that her blood runs cold and she realizes what he'd actually asked for. Not just any crayon. The peach crayon. Somewhere on that boy's body is the answer. No.

She learns through careful eavesdropping that the boy is named Stiles Stilinski – well, he goes by Stiles, at any rate. His best friend is Scott McCall, whose Mark ("Thanks!") is on his right forearm. After even closer inspection, she notices Stiles's – sure enough, the word "no" is dark and defined on his left wrist. He seems to have made at least some kind of a connection, because for a few days, his eyes follow her everywhere, seemingly mesmerized.

He doesn't pluck up the nerve to bring it up until fourth grade, when he sends Scott over on the playground to ask her something. Scott looks very sheepish, stuffing his hands in the pockets of his jacket and shifting from one foot to the other. "Stiles wants to know if he can see your Mark?" Scott says, with an apologetic smile.

Lydia opens her mouth to give him a flat no to take back to Stiles, but then thinks better of it. "Absolutely not," she says primly, before getting out of her swing and walking off without a backward glance.

Stiles doesn't ask her about it again, seemingly stung by her response to Scott's simple question, but he does continue to be in love with her. At least, he seems to think he's in love with her. Lydia of all people knows that love isn't real, and that Marks are probably random and stupid, anyway.

Years pass, and invariably, she always ends up in at least one class per year with Stiles. The alphabet dictates that she's always a row away from him, but she's usually to the left of Scott, meaning she might as well be right next to Stiles. He tries to strike up conversation with her occasionally, but she always keeps her responses as minimal as possible. Every time she looks at his wrist, that "no" is still there – fainter than it had been in third grade, but still very visible. She almost pities Stiles. Hopefully it will fade away completely if she keeps him at arm's length forever.

High school changes things. She meets her new best friend and Scott McCall finds his soulmate – not necessarily in that order. Allison and Scott are nauseatingly infatuated with one another, but Jackson gets less and less infatuated with Lydia by the day. She's seen his Mark – it's on his stomach, and says "shut up", and while she finds that hilarious, it's not the first thing she ever said to him, and he definitely didn't ask her for any crayons.

Her own Mark is every bit as faded as Stiles's, although nobody ever sees it anymore except Jackson (she keeps it covered with a dab of waterproof concealer when she wears swimsuits), and he only asks about it once.

"So, has anyone ever asked you for a peach crayon?" he whispers in her ear one night. He's an asshole, but he's damn good in bed, and sometimes she almost hates him for it.

"Shut up," Lydia says automatically, and Jackson laughs wickedly at the irony.

They're not soulmates, but they share the same beliefs. Love, real love, isn't freely occurring. It's a ship that passes in the night, too rare and fleeting to be worth searching for. That being said, she and Jackson do care about each other, and maybe someday, Lydia could see herself marrying him, if only for potential children and security.

Jackson has other plans, because he breaks up with her. In the aftermath, Lydia's licking her wounds and all too easy for Allison to push onto Scott McCall's best friend, the dateless Stiles Stilinski. She resigns herself to a night at the dance spent avoiding him, but she surprises herself by ... having fun.

That is, of course, until something monstrous finds her on the lacrosse field.

Later, she vaguely remembers someone screaming – "Lydia! Run!" – and she assumes it's Jackson, since she's told he's the one that carries her back to the school and finds help. It's only later, when she's in the shower at the hospital, that she notices her Mark is slightly darker than before. She doesn't have time to dwell on it, however, because that's when her mind starts rebelling against her own careful control of it.

She's dragged into a world of hallucinations and darkness and Peter Hale, and for a while, thoughts of anything else leave her consciousness. She is but a tool for him to use, meant to be thrown away when he's done with her. She hopes he'll be done with her soon.

She's scared for herself, scared for Jackson, scared for them all – and she barely notices when Stiles worms his way into her life. It's only in yet another aftermath, when she's licking her wounds once again (only this time Jackson's texting her from the airport, telling her his flight is boarding and he'll call her sometime), that she even spares her Mark a thought at all. It's about the same as it had been before, but she's starting to suspect – very quietly, buried in the back of her mind – that no matter how far she pushes Stiles away or how much research she does on Marks, it might never fade away for good like she'd hoped. She'll just have to deal with it, then.

Hanging out with Stiles starts to become commonplace (even though Allison and Scott are going through a rough patch – not unheard of for soulmates whose parents disapprove), and although Lydia keeps an eye on it, her Mark doesn't darken too much. Maybe distraction is key, she thinks. She certainly has other things to think about – things like school and sacrifices and finding out what the hell she is. She barely has time to consider the infectious nature of Stiles's grins, the whiskey warmth of his eyes, the way he still looks at her like she's everything.

She doesn't notice just how much he's grown to mean to her until he's panicking in the hallway, half sobbing and half wheezing, and then she's panicking too and dragging him into the locker room. He needs someplace quiet, she thinks, babbling about friends and family and we're so close to each other and then – she kisses him, and the skin on the inside of her thigh blazes like she's been struck with a branding iron.

"How'd you do that?" Stiles whispers in the moments after, when Lydia is staring at him, unable to think of anything other than the tingling of her Mark.

"I, uh, I read once that holding your breath could stop a panic attack," she half whispers, even though she's never read such a thing in her life. "So when I kissed you, you held your breath."

"I did?"

"Yeah. You did."

"Thanks," he says. "That was really smart." It's something that he might have said a million times over, after she's corrected him or helped him solve a piece of one puzzle or another, but it feels different. Meaningful. When she chances a glance downward, his wrist is exposed slightly by his jacket sleeve; the word no is as black as pitch against his skin. Lydia starts to say something else – starts to ask if his Mark is burning, too – but the boldness of the no almost slaps her in the face. It's like a sign, one last warning that if she does this, if she crosses the line in the sand she herself had drawn years ago, she'll be opening herself up to a world of hurt.

She doesn't mention it, and neither does he. And then, soon enough, it's too late.

Apparently, one side effect of being taken over by an evil spirit is that your Mark starts to fade. Stiles's goes from thick and black to faded and gray in the span of a few weeks, but Lydia's doesn't change at all. Now that they're tied together supernaturally – her hands had been the ones to push him into near death back in Deaton's office, after all – as well as naturally, she can sense him in a way she hadn't been capable of before. She can feel his fear, his pain, the clawing nastiness in him struggling to take hold. Her Mark twinges all the time.

Getting Stiles back is not without sacrifice. Allison dies with her Mark still blazing, but Scott's turns to a scar almost as soon as the life drains out of her. Later, once the Nogitsune is gone, Lydia weeps for Scott, for Allison, for all of them.

As cliché as it sounds, however, Allison wouldn't want Lydia to cry forever, so she doesn't. Lydia knows what Allison would say – "Why don't you just talk to Stiles?" – but Lydia has never been any good at taking advice. At any rate, Stiles starts dating Malia, and then it is well and truly too late.

Stiles and Malia aren't soulmates, of course. Malia's Mark is on the back of her knee – "Get out of my way." – but they seem happy. And as for Scott, a few months after Allison's death, something unheard of happens – a new Mark appears one morning on the back of his neck. It's the first sentence Kira Yukimura ever spoke to him. Lydia supposes if anyone out there could buck tradition and have not one, but two soulmates, it's Scott.

Through the course of Stiles's relationship with Malia, Lydia keeps tabs on the state of his Mark. It's darker than it had been while the Nogitsune had possessed him, but lighter than when Lydia had kissed him all those months ago. She keeps waiting for the day that she glances at his wrist and finds it completely faded away, but that day doesn't come. Not even through that shit with the Benefactor, or the doctors – not for the entirety of senior year.

She finds out about Stiles and Malia in the most mundane of ways. She checks Facebook one morning in early June – on her laptop, because her phone had been the only casualty in last night's moonlit escape from vampires with the pack (yes, vampires) – and there it is, right at the top of her News Feed. Stiles Stilinski is now single.

She doesn't have time to process her emotions, because now that she's logged in, she can see that there's a message waiting for her. Predictably, it's from Stiles.

Text me when you get your new phone, he'd said around 4 AM. It's now 11 AM, seven long hours later.

Lydia stares at the words, then at the relationship status update. She can't help but feel that this is another one of those signs, almost like the word no staring back at her from Stiles's wrist, but this time telling her to do the opposite. She hadn't been ready then. She hadn't wanted it for long enough. If she'd gotten it, she surely would have ruined it to save herself.

But she's been waiting for over a year, and even though it's always been her own fear holding her back, something inside of her is saying do it. Do it now while you still can.

She looks back at the message in in her inbox, Stiles's plea for her to text him. She does him one better and goes to his house – after a shower and a change of clothes, obviously. Lydia wouldn't be caught dead out of the house with unwashed hair, even in a situation like this.

The Sheriff is at work when she pulls into Stiles's driveway, but the Jeep – still clinging to life after all this time – is out front. Stiles answers the door after her knock, and looks surprised to see her. He's also quite bedraggled, like he hasn't slept at all since she last saw him – which had been at two o'clock this morning, running through the woods half-blind in the dark.

"You know, nobody our age really uses Facebook anymore," she says, as a bit of an icebreaker.

"What?" he says, squinting at her in the sunlight. "Oh. You got my message."

"Yeah," she says. "Can I come in?"

He lets her in, and they go up to his room without speaking a word. Lydia's stomach is a knot of nerves, and half of her brain is telling her leave, go home, it's not worth it. The other half is just bone tired of waiting to find out.

She sits down on his bed, the way she'd done back in the days before Malia. Lydia's never thought of Malia as anything less than a friend, which means she's always respected the unwritten rule about lounging around on somebody else's boyfriend's bed. Now, however, she needs to be someplace she's comfortable. Stiles perches next to her like a large, lanky bird.

"Did you and Malia have a fight?" she asks. It's not exactly discreet, but they live in a world with werewolves and vampires and God knows what else – she's wasted enough time being discreet.

"We broke up," Stiles says calmly, although he doesn't look at her as he says it.

"Oh," Lydia says. "I'm sorry."

"Don't be," Stiles says, finally shifting his gaze to hers. He looks thoughtful. "She met her soulmate last night. Wanted to take some time to explore that."

Lydia hadn't expected that, and she knows it must show on her face. "Last night?" she repeats blankly, not understanding. Unless Malia has the power to be in two places at once, Lydia can't see how she could possibly have –

"One of the vampires told her to get out of his way when she tried to fight him," Stiles says, and Lydia is relieved to see that he actually looks slightly amused by the idea. "Malia's response was 'fuck you', which happens to be that guy's Mark."

Lydia takes a few seconds to process that. Malia's soulmate is a vampire. Lydia half expects to look out Stiles's bedroom window and see something porcine fly past.

"Are you okay?" she finally asks. She remembers all too well how it felt to lose Jackson and Aiden and Jordan, and none of them had been her soulmates.

Stiles nods. His fingers are tapping away at his knees, but Lydia can't tell if the tic is from nerves or exhaustion or both. It's slightly endearing, but distracting. Lydia can see his Mark clearly from her position – it's slightly darker than she remembers. Heartened, she starts to speak, but Stiles says, "I've been up since Malia left, thinking."

Lydia closes her mouth and nods, waiting for him to continue. Finally, he says, "You probably don't remember, but in the third grade, I asked you for a crayon. That's how we met."

Surprising herself, Lydia says quietly, "I remember."

"You said no," he says, glancing over at her. Absentmindedly, he strokes his right index finger over the word on his left wrist. Lydia is momentarily struck by the effect his hands still have on her, after all this time. She hasn't been this close to him in so long that she'd forgotten how intoxicating it is. "For a long time, I thought you were my soulmate."

Lydia wants to say you are, but the words die on her tongue. "Fuck it," she says abruptly, and stands up.

"Lydia?" Stiles says, confused.

Without pausing to think this decision through, Lydia reaches for the zipper of her skirt and tugs it down with a shaky hand. Her skirt falls to the floor with a soft rustle, and Stiles just gawks at her. Her blouse is long enough to hide her underwear from sight, but only if she doesn't move from this position. "Do you remember in the fourth grade when you wanted to see my Mark?" she asks, her heart thrumming in her chest. Stiles has seen her in a bikini before, but this is different – she has no makeup hiding her Mark now. All it takes is a slight shift of her leg and there it is, black against the pale white of her thigh. "Well . . . here it is."

Stiles just stares at her leg for a moment, and Lydia swallows, momentarily self-conscious. This could all still be a huge mistake, she realizes. She's standing on the precipice, and Stiles can either pull her back or push her over the edge. Vaguely, as if from decades ago, she remembers something – it's not just someone to hold you under, it needs to be someone who can pull you back – and she feels less scared.

"Lydia," Stiles finally blurts, as if he's been trying to speak for a while and only just managed to get something out. "You never told me – why did you not tell me?"

"I was afraid," Lydia admits. It sounds stupid, and she hopes to whatever god is listening that Stiles gives her a chance to explain.

Stiles just stares at her, mouth gaping, and even though she can tell he's still struggling to accept the fact that she's basically lied by omission for a decade, there's also that familiar look in his eyes – the look that says you are everything, you are tethered to me in every way there is.

The pause stretches on for several seconds, and then without a word, Stiles stands up. Lydia didn't wear heels today, so for a change he towers over her. He's so close to her, and God, why did she deny herself of this so long? Even having him close for this short amount of time is better than never having him close at all. "Are you still afraid?" he asks, nervous energy written all over his face.

"No," Lydia says, and later, when she asks about it, Stiles will mention that this is the exact moment his Mark burned and went darker than it's ever been before. In the meantime, however, he's too busy kissing her to tell her.

Lydia loses track of time for quite a while – when she comes back to reality, she's down to only her underwear and Stiles is shirtless and leaning her back against his bed. When he slides off to kneel on the floor, face between her legs, he looks up at her, grins, and presses a triumphant kiss to the inside of her left thigh.

Despite herself, Lydia smiles.