Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/
works/1057502.
  Rating:
      Explicit
  Archive Warning:
      Choose_Not_To_Use_Archive_Warnings, Underage
  Category:
      F/M
  Fandom:
      Teen_Wolf_(TV)
  Relationship:
      Derek_Hale/Stiles_Stilinski
  Additional Tags:
      Female_Stiles_Stilinski, Alternate_Universe_-_Always_a_Different_Sex,
      Cunnilingus, Het, Sex, Menstruation, Menstrual_Sex, Menstruation_Kink,
      First_Time, Genderplay, Smut
  Stats:
      Published: 2013-11-24 Words: 3211
****** Not So Black and White ******
by Moit
Summary
     Always-a-girl!Stiles stays home from school because she gets her
     period for the first time in years and Derek shows up asking why she
     smells like blood. Unapologetic smut ensues.
Notes
     This is set sometime during season one, but that's not terribly
     important. Basically, it's just smut.
     Spoilery trigger warning at the end.
See the end of the work for more notes
Stiles had been a tomboy all of her life. She wore t-shirts and jeans and
played with matchbox cars, and her best friend was a boy. After the death of
her mother, it was easier for her to cope by hiding behind a buzz cut and an
androgynous nickname. After Scott was bitten by Peter, however, Stiles' world
began to unravel again. The stress of having a werewolf for a best friend and
the trouble they had been getting into was beginning to affect Stiles for the
worst, and the increased dose of Adderall she was on was starting to interact
badly with the birth control she was on, giving her migraines. Her nurse
suggested taking her off the pill temporarily, just to see if that helped with
the migraines.
Naturally, that meant that her next period was bad enough to keep her out of
school. Her father had to work, so Stiles was upstairs in her bed wearing her
favorite batman pajamas with a heat pack on her lower stomach in an effort to
alleviate the cramps. She had already taken multiple doses of Tylenol, but
nothing seemed to be working.
In the middle of a Babylon 5 marathon she was watching in an effort to keep her
mind off the pain in her uterus, Derek crawled through her window. If ever
there was a time Stiles wished she had locked the damn thing, this was it.
"I saw the Jeep out front. Why aren't you in school today?"
Stiles exhaled slowly and kept her eyes on the television as she fought to
control her heartbeat. "I'm sick. Isn't it obvious? What are you doing here,
anyway? Don't you think it's a little creepy that you just 'happened' to drive
past my house?"
Derek shrugged one leather-clad shoulder. He glanced around the room as if
looking for signs of sickness. His nose twitched and he arched an eyebrow.
Stiles' heart sank.
"Stiles, why do you smell like blood?" he asked, scenting the air more
obviously.
"I--I don't--Derek, really--It's just--" She didn't get to a full sentence
because Derek was all of a sudden dragging the blankets off her body. He braced
his hands against the mattress on either side of her and began scenting to find
the source of the blood. The closer he got to the origin, the harder Stiles'
heart beat. She knew it was time to come clean. "Derek, I have a confession to
make," she all-but squeaked.
The werewolf paused with his head above her thigh, nose twitching with
interest.
"I'm," she licked her suddenly dry lips nervously, "I'm actually a girl. I just
never really stop anyone when they assume I'm a guy. Surprise?" she said,
sounding much more unsure of herself than she ever had.
What followed seemed like an eternity of silence, during which Stiles thought
her heart would crack and split open into multiple pieces. Practically since
the day they met, she and Derek had been dancing around one another so much
that the others were all-but taking bets on how long it would take them to get
together. This would surely prevent that from ever happening.
Derek cocked his head to the side like an interested puppy. "You're on your
period."
Stiles stared at him. "Did you hear anything I just said? I'm not a dude. I
have boobs!" She rubbed her hands over her close-cropped haircut in
frustration. "I've been lying to you, Derek, and getting away with it."
Irritated and suddenly too hot, she yanked the heat pack off her body and
dropped it on the floor.
"Stiles," Derek said, sitting back on his haunches and placing one of his large
hands over the entirety of her hip. His thumb began rubbing a distracting
pattern over the slip of skin between her top and bottoms. His skin felt even
hotter than the heat pack she'd just removed. "I'm not going to like you any
more or less than I did yesterday just because you have different plumbing." He
lifted himself back up onto his hands and knees so that he could lean down
close enough to kiss her. "And the scent of your heat is driving me kind of
crazy right now."
"I'm not in heat, you loser. I'm just on my rag," Stiles said, pushing at
Derek's shoulder ineffectively.
"My wolf doesn't know the difference." Derek's breath was a hot fog over her
face and Stiles felt a gush of wet between her legs that was absolutely not
blood.
"I've a virgin," Stiles whispered meekly against Derek's lips.
"I'll be gentle."
Stiles' breath caught as Derek's hands moved to the buttons of her pajama top.
He allowed the fabric to remain where it fell, only revealing a slip of pale
skin from her collarbone, down the valley between her breasts. As the cool air
of the room hit her heated skin, Stiles' felt her nipples perk in response.
Derek's gaze flicked up to her eyes briefly, as if asking for permission. She
sucked her lower lip into her mouth and nodded once, sharply.
The fabric of her black and yellow Batman pajamas parted under Derek's
fingertips, the calloused texture grazing her nipples. His eyes met hers again,
and this time he kept her gaze as his thumbs encouraged her nipples into hard
little points. Stiles couldn't stop the soft little sigh that escaped her lips
as Derek worked on her breasts. One of her hands came up to clutch his
shoulder, blunt nails digging into the fabric of his leather jacket.
"God, why are you even still wearing this thing?" she asked, pushing it off his
shoulders with both hands.
Derek let go of Stiles' nipples long enough to shrug out of his jacket and toss
it to the floor. When he returned, it was his mouth instead. This time, Stiles
did squeal, digging her heels into the bed.
"Shh," Derek mumbled against the soft skin of her breast, sliding one hand up
her body to press his first two fingers against her lips. "Someone might hear
you."
Stiles' groan was cut short when one of Derek's fingertips slipped into her
mouth. She latched on instantly, laving the pad of the finger with her tongue
as she mimicked motions of the mouth on her breast.
Derek released the nipple in his mouth, blowing on it softly. When Stiles
wiggled in response, he took the nub softly between his blunt human teeth and
looked up and her with a cheeky grin. Reaching up, Stiles wrapped her long
fingers around Derek's wrist. She pulled his finger out of her mouth so she
could say, "Cute, Fido."
Derek's growl turned throaty and lupine. He turned his attention to her other
nipple, eliciting more noises of pleasure from the girl's throat. Stiles felt
it all the way down to her core.
"Come on, Hale, I never had you pegged for the slow and patient type. What
happened to all that grr you had when we met?"
A moment later, Derek was kissing her. It was her first kiss (kissing Scott
when they were 8 didn't count) and it was a good thing she was laying down, or
else Stiles might have fallen. Derek's hand cupped her cheek as his tongue
mapped the inside of her mouth. Stiles rolled her hips into his body and--Whoa,
that's a dick, her pleasure-addled brain supplied. Instead of freaking her out,
it just made her wrap a leg around Derek's hip, desperate for more friction.
"Is that growly enough for you?" Derek asked, burying his nose into the skin
behind Stiles' ear, and his voice was all wolf.
"Getting there," Stiles whimpered, lifting her chin to reveal more of her
throat. The feeling of his stubble against her skin was almost enough to make
her lose it. She slid one hand into the back pocket of his jeans in an attempt
to press his hips harder into hers.
"I want to eat your pussy," Derek whispered, licking a wet stripe underneath
Stiles' jaw.
Another rush of wetness soaked Stiles' panties even as her stomach clenched
with anxiety. "I don't know about that," she said, squirming beneath Derek's
touch, but the werewolf wasn't listening. He was too busy trailing kisses down
her chest, over her quivering belly, moving ever closer to the apex between her
legs. "Derek," she tried again, patting him insistently on the shoulder as his
fingers inched the waistband of her bottoms lower on her hips.
He paused to raise an eyebrow when he had her bottoms low enough to reveal her
Robin briefs. "Really, Stiles?"
"They go with the outfit," she frowned.
Derek just shook his head and pulled the fabric down and off her legs.
"Wait," Stiles said, reaching out to stop Derek before he could lay his hands
on her underwear. "Let me just . . . " She disentangled herself from his body
and swung her long legs over the edge of the bed.
"Where are you going?" Derek asked, sitting back on his heels again.
"You'll see," Stiles called over her shoulder as she disappeared into the
bathroom. She appeared a moment later nude but for the folded towel held
strategically in front of her body. Derek's eyes drank in the sight, as
evidenced by the bulge in his jeans. Stiles kept her own eyes fixed firmly on a
point that was not Derek, painfully aware that her cheeks were on fire. "Get up
a second," she said, shaking the dark blue towel out.
Still staring unabashedly, Derek stood up and waited patiently while Stiles
laid the towel across the bed. "Okay," she said, laying back down, but modestly
keeping her knees together. "I don't know about you, but I don't like cleaning
blood out of my sheets." She wiggled a bit until her hips were centered over
the towel.
Derek crossed his arms over his body and pulled his t-shirt off in one smooth
motion. The muscles in his arms and chest rippled with preternatural strength.
Stiles had to stop herself from groaning at the sight. Instead of crawling back
on top of her, however, Derek settled himself against her side, his fingertips
playing along the soft skin of her thigh. To keep up appearances, she did not
shave any part of her body except for her bikini line, which nobody would see.
Derek's eyes did not, as she would have assumed, zero in on the one place she
wanted him most, but it allowed her body to relax by fractions.
"I'm not going to hurt you," Derek said gently, and with each stroke of his
hand, he was gently encouraging her thighs to part until the knee closest to
him fell to the bed, revealing her to his gaze. "You are so beautiful," he
said, but his eyes were trained on her face.
"Stop it," Stiles giggled, smearing her grin into the pillow beneath her head.
"I already said yes; you don't need to talk me into it."
"I'm not trying to talk you into anything." Derek's eyes remained locked on
hers as he placed his hands on the inside of her thighs and lowered his head.
His gaze flicked downward and he inhaled deeply through his nose. When he
looked back up, his eyes were bright blue. Stiles didn't even try to stop the
noise that came out of her throat.
At first Derek didn't even touch her; he just breathed against the sensitive
folds, making her writhe and squirm with frustration. Not even when she fisted
his hair in both hands did he give in. If anything, it seemed to inspire more
teasing.
Finally, when Stiles thought she might go mad from the touch of Derek's hands,
his mouth, everywhere but at her core, he licked a long, wet strip between her
pussy lips and over her clit. Any embarrassing thoughts she had about being on
her period were immediately thrown out the window. Her world narrowed down to
the throbbing between her legs and Derek's mouth.
When she thought she could go just from the feeling of Derek's tongue, he
pulled away and slid one long finger inside of her. Stiles' mouth fell open in
a silent gasp. Her hips swiveled wantonly, begging for more.
Derek lowered his face to her clit once again, bathing the tiny bundle of
nerves in saliva. It didn't take Stiles much longer to reach her peak. She
came, clutching tightly to Derek's hair with both hands. Had he been human, he
might have objected more. He didn't pull away until the tremors in Stiles' body
subsided. When he went to kiss her, however, she turned her head.
"That's gross."
"It's completely natural." He did not, she noticed, have any . . . evidence on
his face.
"It's completely natural to both bleed from the vagina and to perform oral sex.
It is not natural, however, to put one's menstrual blood in one's mouth." She
raised her eyebrows in challenge.
Derek just shook his head and chuckled. "You are something else," he said,
settling for sucking a mark into her shoulder instead.
"How about you?" Stiles said, tucking her fingertips into the waistband of the
jeans he still wore.
"Are you up for it?" Derek slid his hand back down between Stiles' legs,
pulling a gasp from her throat as he stroked her oversensitive skin.
"As long as you promise not to knot me."
Derek's expression morphed into one of confusion.
"Kidding!" Stiles said. "Don't you ever use the Internet? Some people are into
that sort of thing."
"I don't even want to know," Derek said, shaking his head. Since there was no
graceful way around it, he stood up from the bed again to shuck his jeans and
boxers. When he returned, Stiles was treated to an eyeful of nude, adult male
werewolf. Her body shivered in anticipation. "Are you cold?" Derek asked.
"I won't be in a minute," Stiles said, reaching out to encourage Derek closer.
He settled into the v between her legs, hard cock resting against her hip. "Did
you bring a condom?"
"I'm a werewolf," was Derek's immediate response.
"That's fantastic." Stiles rolled her eyes. "Did the werewolf bring a condom?"
"Stiles, I can't catch or carry a disease. I'm clean."
"I could still get pregnant."
"But you're on your period."
"But I still could." Stiles stared into Derek's eyes; neither of them seemed
prepared to back down, and Stiles wasn't inclined to drive down to the
Walgreens right this second. "If I do get pregnant, promise me you'll pay for
half the abortion," she said seriously.
"Stiles," Derek started, but she cut him off.
"Promise me, or I'm kicking you out."
"Fine," Derek said, cupping her face in his hand and running his thumb over her
cheekbone, "if by some miracle I manage to impregnate you, I will do the right
thing and pay for the abortion."
"Thank you," Stiles said, leaning up to kiss his nose. "You may proceed to
deflower me."
Derek reached down between her legs to ensure that she was still sufficiently
wet before taking himself in hand and pressing forward. At Stiles' soft gasp,
he stopped, worried eyes trained on her face. "Did I hurt you?"
"You're just a lot bigger than . . . I can't say than I was expecting, because
I certainly wasn't expecting this, but definitely bigger than anything I've
ever imagined."
"I'll go slow," Derek promised. He paused after nearly every millimeter, just
to ensure Stiles was still with him. Her eyes were closed tightly and he could
see tears leaking out of them at the corner, but still she urged him on. When
he was fully seated, he buried his face in the juncture between her neck and
shoulder. "You are so tight."
"Make no mistake, Sour Wolf, this fucking hurts," Stiles sighed, wiping at the
tears in her eyes.
"Do you want to stop?" Derek asked seriously.
"No." She drew her knees up on either side of Derek's body, bracketing him in
and changing the angle slightly. "Rumor has it that it gets better."
"That's what I hear." Derek rubbed a hand over her shorn hair. "Just tell me
when."
After several tense, silent minutes, Stiles nodded. "Okay."
Derek lifted himself up onto his elbows. He watched Stiles' face as he slowly
pulled out and pushed back in again. Her eyes screwed up tightly, but her mouth
fell open with a soft sigh. "Yeah?" Derek asked rhetorically.
Stiles hummed in response. She hooked a hand around the back of Derek's neck
and dragged him back down for a kiss. Her hips began to move of their own
accord, meeting Derek's at every thrust.
"Do you want to try a different position?" Derek asked after a beat.
"I'm good," Stiles replied, sliding her palm down the sweaty expanse of Derek's
chest.
"You sure?" Derek asked. "I could maybe do you from behind? Or put you on top?"
He reached for her knee, lifting it higher to drive himself deeper inside her
body.
"Thanks, but I really don't like the idea of you treating my breasts like
handlebars."
Derek was so stunned he could only stare at her. Stiles shut his jaw with a
soft click. "Don't do that. You'll catch flies."
"You are one of a kind."
"So I'm told." Stiles linked her ankles around Derek's back. "How long are you
planning to go for? I mean, I'm not complaining, but I don't think I'm a
marathon sex kind of girl."
"I was kind of hoping to get you off again," Derek said, snaking a hand between
them to rub against Stiles' clit.
"Thanks, but no," Stiles said, pulling his hand away gently. "I'm just a bit
over-sensitized right now."
"We'll work towards that next time." Stiles didn't have a chance to reply
because Derek was soon moving at a pace fast enough to take her breath away. It
was all she could do to hold on.
Suddenly, he pulled out and began jacking himself furiously. He came with a
harsh cry onto the skin of Stiles' belly.
"Wow, dude," she said, looking from the mess on her stomach to Derek's face,
"gross."
Derek just shook his head and chuckled. "Well, it was either that or inside
you, and we already discussed how you feel about being cast on 16 and
Pregnant."
"Wait," Stiles said, her expression serious, "Did Derek Hale just make a joke?
Mark this day down on your calendar, ladies and gentlemen."
Derek leaned down and placed a gentle kiss on Stiles' lips. "Do you want to
shower? I'm sure you don't want to lay around covered in my spunk all day."
"I don't know, it has a sort of je ne sais quois quality about it," she said,
while dragging herself up off the bed. A red-tinged slick of wetness began to
slide down her inner thigh. "On second thought, I do need to . . . tend to
myself." She paused at the door to the bathroom, throwing a glance over her
shoulder. "Are you coming?"
Grinning, Derek stalked forward, looking like so much more man than he had
moments before.
After a joint shower, Stiles was snuggled up in her batman pajamas with Derek,
a werewolf furnace, at her back. No medication could compete with him.
End Notes
     TW: In conversation, Derek agrees to pay for an abortion in the event
     that Stiles gets pregnant.
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