They're seven years old, sitting on swings and absently swinging their legs through the air. The other children run and laugh and play, all so naïve and average and normal.

But while the others scream and talk about superheroes and dolls, they're considering what the correct amount of sodium bicarbonate would be to create optimal flow on their baking soda volcano.

It's simple, easy and them. No one else cares, and they themselves had long since given up trying to associate with their peers. The others didn't understand them like they did.

That is, until the pretty girls flock around Jemma whilst Fitz looks on nervously.

Raina steps forward first, tugging the popular boy Trip so he's next to her. He shoots them an apologetic grin, wincing at the smirking girl next to him.

"What's wrong, Jemma?" She asks, sugar-sweet voice dripping with mockery. "Why are you so alone?"

Jemma hesitantly lets her gaze dart between Raina, Trip and Fitz, who looks bashful. She swallows. "I'm not alone. I have Fitz,"

Raina lets out a puff of breath. "But he won't hold your hand. Not like my Trip, or Grant, or Lincoln."

Jemma pushes down the urge to correct her grammar. "Well, what's so great about holding hands?" She huffs back. "No woman needs a man. Unless he's holding her purse while she kicks the bad guy's butts."

A small grin blooms on Fitz face. Of course Jemma wouldn't hesitate to talk about her idol Peggy Carter.

"That's true," Raina smirks. "But that doesn't make you cool."

A few of the other girls snicker, making Jemma look abashed. A light blush coated her cheeks, but she didn't answer.

"That's what I thought." She turned on her heel. "Come on, girls!"

Trip mouths a "sorry" over his shoulder before he's disappeared into the crowd.

Jemma sighed, scuffing the toe of her sneaker into the dirt. Fitz didn't miss the way the excitement that lit up her eyes as she talked about science had diminished after the girls attacked.

"It's not fair that they talk to you like that," he whispered softly.

Her eyes flicked to his before retreating back down. "Mum says they're just jealous."

Another silence lapsed between them, Fitz sadly watching the other children play. No one wanted to hang out with them except Bruce, and that was only when Tony wasn't convincing him to help build another haphazard invention.

"I could hold your hand," he offered quietly. "It's what friends do, yeah?"

Her head shot up to look at him. "Really? You'd do that for me?"

He grinned at her burst of liveliness. "I'd be honored."

The bell rang shortly after, and Jemma excitedly slipped her palm into his. Her pigtails bounced merrily as she pulled him across the school yard and into the hallway.

She stuck her tongue out at Raina's slightly shocked face before ducking into their class room with Fitz.

Somehow, their hands fit together snugly. But when Jemma tried holding the new boy Will's hand later that day, it didn't feel as right as Fitz's had.

So if she held Fitz's hand all the way up to his doorstep, she was just expanding her range of data.

Five years come and pass, and all too soon middle school has begun. It's a brand new territory with lockers and bells, but somehow she doesn't feel too lost when Fitz is holding her hand.

Their lockers are stuck right next to each other, because they wouldn't have it any other way. They know each other's combinations by heart, and two schedules hang side by side in each locker - one for them, and one to keep track of the other.

The first event that breaks apart their weekly Doctor Who nights is Jemma's first slumber party. It's not exactly her first - countless nights have been spent in pillow forts with Fitz right next to her - but it's the first one with just girls. The one where everyone stays up all night and watch movies, play games, and talk about boys.

Daisy, Bobbi, Natasha and Pepper are there, but so is Raina. That's where the fun begins.

"So," Raina starts off casually, tossing a popcorn kernel in her mouth. "Who was your first kiss?"

Daisy grins sheepishly. "Lincoln. He's so cute,"

The girls all coo as the circle goes around, all seemingly having found the boy of their dreams despite being only twelve years old. Jemma knows logically that the odds of a relationship getting all of the way through high school, let alone middle school, is slim. But the girls don't seem to mind.

"How about you, Jems?" Bobbi asks. She can tell it's not meant to be rude, just a simple question.

"I . . . I haven't. . . Yet," she manages to stammer out. Her cheeks are flaming, worsened by the sympathetic looks the girls are shooting her.

"Poor thing," Raina scoffs. "Never going to find a man."

Natasha looks murderous - after all, who invited Raina anyway? - but Pepper's hand on her shoulder seems to calm the red head down. Jemma sighs heavily and pulls the sleeping bag over her head.

Monday comes soon enough, and her hand is twined with Fitz's as they walk to school. She swallows heavily before starting in on the speech she planned out all weekend long.

"So have you kissed anyone yet?" She asks tentatively.

His head snaps up to stare at her. "I'm sorry?"

"Have you had your first kiss?" She clarifies, even though she knows he heard her the first time.

His free hand scraped at the curls at the base of his neck. "I, ah, no,"

Jemma nods, taking it in. "Neither have I," she adds after a moment.

Fitz nods in return, trying to come up with a reply. She beats him to it.

"You should kiss me,"

He looks at her as if she's grown a second head. "Why?"

Her cheeks feel hot. "I . . . I don't know. I just think my first kiss should be with someone who matters."

He's quiet, mulling it over. Just when she thinks he's going to stay that way, his head is dipping towards hers and his lips catch hers in a soft kiss.

He brushes his mouth gently over hers, careful but exploring. He's warm and soft and pliant as she cups his cheek with her hand. It feels nice, she decides.

But then she breaks away, giving him a small, breathless smile. And just like that, they're back on their way to school.

The following Friday, they're back at Fitz's place watching their show as every week. Their legs are curled up under the blankets together as she leans her head on his shoulder.

But then he looks down at her blearily, and she looks back up at those blue eyes, and she tilts her face up just so . . .

Their second, third, and fourth kisses are shared that night, simple presses of lips to each other's carefully. She's going in for a fifth when he jerks back suddenly.

A shard rips through her heart at his absence. But just as she'd begun to fret that she had just ruined everything, he spoke out softly in the darkness.

"What are we, Jemma?"

His eyes are electric in the glow from the TV set, his tongue darting out to lick at his lips. She offers him a small smile.

"We're best friends," she whispers, reaching for his hand in the darkness. "We're best friends who hold hands and kiss and talk about science."

His mouth quirk up in a smile, and she takes the opportunity to press another kiss to his lips.

They never really date.

Their parents take regular notes on who they are to each other, but they never push it.

Because that's who they are: best friends who hold hands, talk about science, and kiss.

Twenty one comes around, and with it a whole wave of new experiences they've never tried before coming to the States.

They're drunk.

Fitz is staggering home, Jemma hanging on his arm for dear life. The other Academy cadets had insisted they go with them back to the dorms, but the two had been far too wasted to wait for everyone else. So they stumbled home.

They're almost home when she suddenly stops, making him nearly flop face first into the pavement. He mock glares at her - or at least tries to. His coordination is iffy at best.

She giggles at him, then grabs for his hand and pulls him steadily to his feet. "I was just thinking,"

"When 're you not," he tries to roll his eyes, but ends up blinking slowly instead.

She slurs her words with a big grin. "That we should make a baby,"

Fitz stares at her. "Why?"

"Because science, Fitz!" Jemma crows as if it's the best excuse for anything in the cosmos.

He nods seriously at her. Because if science said so, then that means it must be done.

Because science.

The next morning she can't look him in the eye. They're both hung over beyond anything Jemma's ever felt, and from the looks of it, Fitz either.

"Do you remember what happened last night?" He asks as he shields the light from his eyes.

"No. You?"

"Not really,"

She lied.

So she scurries around, collecting her clothes from where they've scattered around his bedroom. Her dress over a lampshade, bra and knickers over some blue prints.

Fitz mumbles an apology, picking up his things as well. She's not there to hear it, already slamming the door to her end of their flat.

Whatever happened that night, they don't talk about it.

She's twenty two, laying in the hospital holding her newborn daughter.

Fitz is right there next to her, watching as she signs the birth certificate. Her eyes dart across it in concentration before putting down a name.

He waits for her to fill in the last name with her own, but it never comes. Instead, she fills it with his.

They have a daughter.

Two best friends who haven't kissed since the eighth grade, and they have a daughter.

They're watching Doctor Who, this time with an extra someone between them. It's Friday, same routine they've kept since the fourth grade.

Fitz is to her left, buried under a mound of blankets with their little girl nestled in an arm. She's barely a week old, curled up on her daddy's elbow.

Jemma finds herself drifting further and further away from the TV set. Instead, she watches her friend and their daughter.

He's so gentle with her, letting her fist curl around his finger. She sucks mindlessly on a pacifier as their blue eyes meet. It's so precious, and she can't help but feel a swell of pride.

Fitz catches her watching, glancing up from his silent staring contest. "What is it?"

"I've been thinking," She takes in a breath. "That maybe we should convert your room into an office."

His eyebrows scrunch up. "Okay . . ." He starts off hesitantly. "So you want me to start taking the couch?"

"No!" She jumped, almost too loud as they had to wait for the baby to return to a comfortable position. "No," she repeated, softer. "I thought maybe we could share a room. Share a bed. To help take care of the little one,"

He's silent for a split second. "Alright," Fitz nods, his eyes meeting hers with a piercing gaze. "But before we do that, I just need to know one thing,"

She nods quickly. "Anything,"

"What are we, Jemma?"

The biochemist freezes, dropping his gaze to watch their daughter instead. Tension lingered in the air before she spoke.

"We're best friends," she said simply, not missing how his hopeful expression fell a bit at her words. "We're best friends who hold hands, kiss, share a bed and talk science who just so happened to have a baby together."

A year comes and goes, and their baby girl isn't quite a baby anymore. She crawls around and can sit up with ease, curls the color of Jemma's and piercing eyes like Fitz.

She can almost sleep through full nights, so there's not much need for her parents to keep in a single bed. In fact, she's been out of the playpen in their room that served as her crib for three months now, but Fitz and Simmons simply won't admit that one of them should go back to their own room.

So they lay together at night, legs intertwined and arms wrapped around the other. Sometimes their little girl will sleep between them snugly, but otherwise it's just the two of them.

The line between friendship and domesticity became increasingly blurred. Sometimes Jemma would lie awake at night and wonder if the man next to her wanted more. And if she was the one holding him back.

"Fitz," she asked boldly in the middle of the night. "What are we?"

His voice is rough, but she can tell it's not from sleep. "I dunno about you, but I'm in love,"

The hand she'd been running over the stubble on his cheeks freezes. As if sensing the disturbance, he rolls over to face her.

"You . . . You what?" She manages, sure she must have misheard him.

"I . . ." He's stiff in the way that means he blurted out something he didn't mean to. "God, Jems, I didn't -"

She cuts him off with a firm press of her lips to his. He's stiff for but a thin second before eagerly moving his mouth back against hers.

Jemma grips him tightly and pulls him closer to her because this. This is what she's been feeling. This is how she can show him where the blurred line between their friendship and their less professional relationship is. And how much she's begun to wish they could cross it.

They break apart finally for lack of air, and even in the dim light from the baby monitor she can make out something in his eyes that she's only just now been able to identify - love. It's something that she had seen in his eyes the day they brought their baby home from the hospital and everyday since.

"I love you," she whispered, caressing his cheek.

He smiled, rubbing the small of her back through the thin shirt as he pressed a softer kiss to her lips once more. "I love you," he returned softly.

He proposes to her three days later, when they're twenty four years old.

"I don't want us to be husband and wife," Fitz whispered, down on one knee. "I want us to be best friends who have kids, kiss, love each other. I want us to be best friends who hold each other's hands through life. Because that's exactly what we've been doing, even if we didn't realize it. Marriage isn't about falling in love - it's about being with your best friend forever. And if I'm lucky enough to be in love with my best friend, then I think that's something I can live with. So, Jemma Simmons, will you marry me?"

She's in tears when she collapses to her knees in front of him, pulling him into a tight embrace as she kisses him fiercely.

"Yes," Jemma beams when they pull back and he's slipping the ring into her finger. "Always yes,"

They're married six months later, because really, there's no point waiting. They've practically been married for the past two years, the ring isn't going to make a difference.

It's a small event held in England, close enough for most of their families to come.

Both of their mums present a scrapbook with various photos through the years, starting with the first day of school right up to graduation. Somehow, they even managed to scrounge up a photo of their first kiss on the walk to school so long ago.

They laugh and cry and kiss through the evening, as the many emotions of a wedding bring. All too soon they're back in the hotel room, holding each other as the night continues on.

Nine years later, they're watching little Peggy skip off to middle school with Daniel, her best friend. Fitz seemed reluctant to let her go.

Jemma finally grabs Fitz by the shirt and pulls him away from the window.

"Let them go," she grins knowingly at him. He pouts.

"But you remember us," he whines like a petulant child. "We were horny little beasts! Kissing and holding hands. . ."

Jemma laughs. "There are worse acts to perform,"

He shrugs, resigned. "Alright, but if he hurts her-"

"Mm, not going to happen," Jemma hums knowingly, gazing over his shoulder out the window.

Fitz spins around to see what she's going on about, only to see his daughter leaning on her toes to kiss Daniel firmly on the mouth.

He's getting ready to grab the ICER - because best friend or not be damned, that's his little girl - but Jemma holds him back and instead snaps a photo.

Peggy beams up at her friend and then tugs on his hand, pulling him along to school.

"That's what we looked like," she whispered to him. "And yet it took us over a decade to realize it."

He nods wordlessly, watching the children's retreating figures on the sidewalk.

"Let's just hope it doesn't take them that long to get it together."