Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/
works/524140.
  Rating:
      Explicit
  Archive Warning:
      Underage
  Category:
      M/M
  Fandom:
      Teen_Wolf_(TV)
  Relationship:
      Derek_Hale/Stiles_Stilinski, demon/Stiles_Stilinski, demon/Derek_Hale,
      demon/Stiles_Stilinski/Derek_Hale
  Character:
      Derek_Hale, Stiles_Stilinski, demon_of_nonspecific_name_and_origin
  Additional Tags:
      Demonic_Possession, Willing_Possession, mild_violence, Demon!Stiles,
      Knotting, dubcon, breeding_(referenced), Unsafe_Sex
  Stats:
      Published: 2012-09-29 Words: 5245
****** Three Can Keep A Secret ******
by ladyblahblah, umbralillium
Summary
     Derek discovers that Stiles has been living with a demon inside of
     him for most of his life. What starts as a confrontation turns into
     something else altogether.
Notes
     This all started out with me mentioning on Tumblr that I'd really
     like to see a demon!Stiles fic wherein the demon just loses patience
     with Derek's bullshit and demands a little respect, seeing as how
     this is his town and the entire pack was there at his sufferance.
     Then umbralillium took that idea and ran with it, and I ran with what
     she ran with, and it turned into a massive round-robin out of
     nowhere. And then it got abruptly filthy. And neither of us were
     sorry.
     Please be aware that this story deals with possession by/cohabitance
     with a demon, and therefore contains elements of dubious consent.
     Please also be aware that this is posted here directly from Tumblr,
     and has all the qualities of a comment fic that such a thing entails.
     Dialogue sort of comes and goes, and this remains entirely unedited.
See the end of the work for more notes
Can I just get a demon!Stiles fic where, like, Derek’s getting all up in
Stiles’s face about something or other, and suddenly BAM, the demon’s out,
throwing Derek into walls and shit like, “You think you’re hot stuff?  You
think you’re the boss of this territory, or anything in it?  Little newly-
minted alpha wolf, please.  You think werewolves are the only monsters out
there, just because that’s all you knew growing up?  Who do you think’s kept
this town as quiet as it has been the past sixteen years?  This is my
territory, mongrel, and you will show some respect.”
And, even though the demon is holding him up by his throat, Derek’s still
snarling and snapping but it’s mostly out of fear because he’s imagining what
this demon could do with its knowledge of the pack. Because, if this thing has
been in Stiles the whole time, it knows everything.
What he doesn’t get—and it frustrates the demon to no end because HOW HARD IS
THIS TO UNDERSTAND, REALLY?—is that the pack is there because the demon is
allowing it.  Seriously, guys, chill out.  It’s kept this town free of almost
every other supernatural threat for the better part of two decades now; do you
really think you’d still be here if it wasn’t okay with the idea?  It’s called
delegation, idiots.  Look it up.
And Derek’s wondering why the demon chose the wolf pack to help him keep Beacon
Hills safe. Why not some of the other supernatural things that it’s implying
have been through here? Why is it even keeping the town safe? Isn’t it supposed
to be all about chaos and destruction? Blood and tears and fear?
Okay, first of all, that’s prejudiced, and demon!Stiles will thank you not to
make frankly racist assumptions about him.  Second: he clawed his way out of
hell for a reason, okay?  He doesn’t really understand other demons who are all
into making this world as awful as that one.  That one sucked.  Stiles much
prefers milkshakes and curly fries and air that doesn’t ring with the torments
of the damned.  Maybe it’s because he managed to get out sooner than the
others; maybe he has more of his humanity left in him; he doesn’t know, and he
doesn’t care.  This world is nice, and no one has found him here yet, and he’s
going to keep it that way.
As for why he chose the wolf pack, well.  They were already here, it was really
just convenient.  He’ll admit he was a little territorial at first; when Kate
Argent showed up, he actually thought it was a good thing.  He could feel the
intent in her, the darkness—oh yeah, she’d be going to the hot place soon
enough, and no mistaking that—and he figured it was perfect.  She’d take out
the only other supernatural things around; it wouldn’t have anything to do with
him so no one would get suspicious; and as long as he laid low, there’d be no
reason for hunters to even look twice at Beacon Hills.
That said.
FFS, do you have any idea how much more work it was to keep the place clean
when he was the only muscle in town?  Having a werewolf pack in town turns out
to be a built-in deterrent for most other supernatural menaces, and once they
were gone he had to work about five times as hard to keep things in order. 
Derek might be a massive failboat of an alpha, but he seems to have the same
goals as the demon, in the end: peace and quiet.
Now shut your furry ass up and go deal with this alpha pack crap.
You were going to USE Derek’s family and you expect him to HELP you? You’re
crazier than Derek originally thought. He’s not your lapdog, you black-eyed
little shit. If you want them gone, you’re going to have to pull your own
weight. Now let him talk to Stiles.
It’s in your best interest to play along, puppy.  If you think he hasn’t been
pulling his own weight all this time, he’s tempted to skip town for a month and
see how well you like things without him there.  See how you deal with the
monsters that start crawling out of the woodwork as soon as they catch the
scent of weakness.  Because that’s what Derek is: weak, hardly able to hold his
mongrel pack together without Stiles’s help.  And speaking of, he can’t help
but grin as he wonders, what makes Derek think there’s a Stiles left to talk
to?
What makes him think that there ever was a Stiles?
So you do the flailing and verbal vomit on purpose? What kind of demon ARE you?
It just glares at him for a second, and it feels weird and wrong to see such a
familiar expression out of jet-black eyes, weird to recognize the way his jaw
clenches as he struggles against something Derek can’t identify.  Until finally
those eyes just narrow even more, and he snarls out,
“Shut up.  Asshole.”  His hand tightens for a moment, until Derek’s eyes
bulge.  “He’s mine, you get that?  I’m the one who stepped in to give this body
more time, to keep it going until the doctors got their shit together.  He’s
mine, and I sure as shit didn’t claw my way out of hell to lose him to the
likes of—”
Which is when that preternaturally strong hand loosens and Derek slumps to the
ground, coughing through a nearly-crushed windpipe as the black leeches out of
Stiles’s eyes.  He looks for a second like he’s going to try to help Derek up,
but he snatches his hands back almost immediately.
“Sorry.  Sorry.  Uh.”  He laughs a little nervously.  “It would probably sound
like a really bad joke if I said he was possessive, wouldn’t it?”
Derek tries so hard not to flinch at the sudden shift from the stranger wearing
Stiles’s skin to the Stiles he’s familiar with. He can’t trust that it’s really
Stiles, though. Not after what the demon said. “Why now? Why are you showing
yourself now? Why not when Scott was turned? Why not six years ago? WHY?”
“Yeeeaaaaah, he’s not gonna answer you; he’s sulking now.”  Stiles does hold
out a hand now; when Derek ignores it to scramble up on his own, he pointedly
ignores how Stiles’s face falls.  “That’s why,” he says shortly, stuffing his
hands in his pockets as he steps back.  “You grew up around people who were all
like you; can you imagine what it would feel like to have the people you love
look at you like you’re a monster?”  A wry, bitter smile curves up his lips. 
“Yeah; of course you do.  That’s why you never told anyone about Kate, right?”
He stalks away and Derek watches carefully.  They even move differently—Stiles
and the thing inside of him—and he’s dizzy from the switch.
“What could we have done six years ago, huh?  You don’t—I saw inside her head,
all right, got inside her thoughts and felt what she felt and … I have a demon
living inside me, Derek, and that woman was the closest to pure evil that I’ve
ever known.  I’d have stopped it, I’d have killed her, with my own hands if I
could’ve. But he wouldn’t let me; we couldn’t figure out how to do it without
it being traced back to me, so he wouldn’t let me.”
“You could’ve told—”
“Told who?  Your family, who thought I was just the sheriff’s kid?  My dad? 
Put him right in the middle of a blood feud between hunters and werewolves?  I
didn’t want to get him killed any more than I wanted to die, myself.  Tell me,
Derek, what the hell was I supposed to do?”  Stiles demands, whirling on him in
a fury, eyes bright with tears he refuses to let fall.  “If you can figure it
out, tell me, because it’s been six years and I still haven’t come up with an
answer.”
Derek looks away, trying to not think about Stiles locked up at 10 years old;
all that energy forced down, boxed up. Not that Derek thought the demon would
have let Stiles waste away like that. For a second he wonders if the demon
would have abandoned Stiles if they’d been caught, but he can’t think things
like that right now. He can’t contemplate how a demon would react in a
hypothetical that makes his chest hurt like this.
“Anyway, you don’t have to worry,” Stiles is saying stiffly.  “I’m not just
going to be sitting on the sidelines on this.  We’re not going to.  I’m just
not sure how much help I’ll really be able to be, considering.”  He shoves his
hands in his pockets.  “He’s got this hang-up about me getting hurt.”
Derek wants to say it’s not a hang-up.  He wants to say that it’s natural,
understandable, and that this thing inside of him doesn’t have the market
cornered on wanting to keep Stiles safe.
Instead, he says, “Why?  It’s not like he can’t keep you alive, right?  What’s
in it for him?”
For a moment, Stiles looks like he’s just been punched, and despite the voice
in his head whispering that this is probably just part of the demon’s long con,
Derek finds himself wishing that he could take the words back.
“Who knows?” Stiles shrugs after a moment.  “Maybe it’s because I keep him
anchored in here—” He taps at his chest even as Derek flinches at the word. 
“—and if he starts being an asshole it’ll be easier for me to let someone rip
him out again.”  Stiles’s smile doesn’t quite reach his eyes.  “Sanctuary, you
know?”
“So it can be done, then.”  Derek’s stepping forward without conscious thought,
intent on what Stiles probably hadn’t meant to let slip.  “We could pull him
out of you?”
“You could,” Stiles says, smile sharpening. “But then you wouldn’t have my
help, anymore. Tell me something, Derek, do you really want me, with everything
I know about the pack, to be mad at you? With this demon in my head, do you
really want to run the risk of him turning vindictive? He let you live once,
what makes you think he’ll do it again if you betray us?”
Derek stands, just staring, because he can’t believe what Stiles seems to be
saying.  He won’t believe it.  But in the end there’s just no choice, no other
way to understand.
“You … like it.  Him.  Having him …”  The words catch like bile in Derek’s
throat.  “Inside you.”
“Wow, way to make it sound hella pervy, man.”  Stiles crosses his arms
defensively over his chest, not quite making eye contact.  “He’s been in here
as long as I can remember, okay?  How would you feel if I suggested just,
like.”  He waves one hand in a vague gesture.  “Removing your wolf?  Huh?”
Derek swallows down the surge of bile that thought brings up. It’s different,
though, he was born a wolf. It wasn’t his choice, but he wouldn’t cha—. Oh.
That’s. Okay. He might be understanding it a bit more, now. It’s just…How does
he know what times he was dealing with Stiles and when he was dealing with the
demon? Or was the demon always close enough that it never really mattered?
He sighs, fighting back the headache that’s threatening to split his head in
half. This wasn’t what he was anticipating when he came to talk to Stiles. He
wasn’t expecting Stiles’s jokes to break his last thread of patience. He wasn’t
expecting to get a dose of his own medicine. He wasn’t expecting Stiles to
match his strength. He wasn’t expecting to feel like Stiles is his equal.
“Okay.”  Stiles nods, apparently taking whatever he reads in Derek’s expression
as his answer.  “Now, no more talk of exorcisms, okay?  It makes us cranky.” 
He rolls his shoulders and moves over to his desk, shuffling through the papers
he’d printed out for Derek to look at.  “I really hope you’re not expecting,
like, a new member of the super-team,” he says abruptly.  “It’s mostly just
like having an extended life bar.  Stiles takes a lickin’ and keeps on tickin’,
thanks to this handy little Hellfire battery.  Patent pending.”
“Says the guy who had me held over his head a few minutes ago,” Derek counters
dryly, and Stiles shrugs.
“He wanted to make a point, and I was pissed off enough at you to let him.” 
His eyes are still locked on the pages in his hand, pointedly avoiding Derek’s
gaze now.  “That was stupid.  I don’t usually let him take over like that; the
more power he’s given the more he’ll take.  That’s how you lose yourself.”
“Sort of a weird sentiment for someone so attached to it.  Him.”
“Hey, we’re buds, but I’m not an idiot.  He’s a demon; it’s just his nature.”
“So … you care about him.”  The words still feel wrong in Derek’s mouth; he’s
never held with the concept of blasphemy, but he thinks that it might taste
something like this.  “But you don’t trust him?”
Stiles does look at him now, with something like his usual grin in place.  “I’m
complicated.”  He straightens, holding out the pages.  Then his eyes widen for
a moment before they squeeze tightly shut and he says, ruefully, “And sometimes
he tries to talk me into really awful ideas, so there are issues there, too. 
Dude.  No.”
Derek frowns, curiosity piqued. “What kinds of awful ideas? Running over a
kanima awful or something worse?”
Stiles opens his eyes again for the express purpose of glaring at him.  “Okay,
first?  Running over the kanima was an excellent idea.”  He shifts uneasily,
thrusting the papers towards Derek again.  “Look, just take the research,
okay?  Before I … do something.  Stupid.  Okay?  You should go.”
“You keep saying that. What’s so stupid about whatever it is?” Derek asks,
still not taking the papers. “What does he want you to do?”
“It doesn’t matter!  God!  Here’s the research you asked for, just take it and
go.”
He steps forward to shove the pages against Derek’s chest.  Derek’s hand comes
up automatically, his fingers closing around Stiles’s wrist, and he feels it at
the same time that he hears it: the telltale skip-jump of Stiles’s pulse when
their skin meets.  Stiles tugs his hand loose, making a choked, annoyed sound
when the papers fall to the floor.  It’s too late.  Derek knows what he felt;
what he heard.
And now that he’s pushing through the sharp scent of jangling nerves, he
finally recognizes what he smells.
Derek steps closer to Stiles, breathing in slowly, cataloging and filtering
through the different scents flooding him: Stiles’s body wash and shampoo, the
burger and curly fries he had for lunch, and, underneath it all, the sweet musk
of arousal. He smiles slowly, eye flicking down to Stiles’s parted lips. “Do
you really want me to go?” he asks, voice low and rough.
There’s a buzzing under his skin, his wolf straining against the firm control
he’s had over it since that day in the woods so many months ago, when he first
caught Stiles’s scent and something primal stirred in his blood.
“Wh-what are you—”  Stiles is scrambling backwards, all desperation and
overlong, flailing limbs, and something inside of Derek seems to settle at the
familiar display.  “Did you get hit with spores or something while I wasn’t
looking?”
“Stiles.  Answer the question.”
“Do I …”  Honey-gold eyes are locked on Derek’s mouth.  Derek feels a surge of
victory, his wolf howling out its approval, and it catches them both off-guard
when Stiles’s scent spikes with something sharp and unpleasant just before he
looks up again.  There’s something like hurt and suspicion in his face,
something that Derek doesn’t understand until he says, “Is this because of
him?  Now that I’m not just the weak little human anymore, suddenly I’m worth
paying attention to?”
“No, that’s not why-not just why,” Derek counters. “You challenge me, Stiles.
You don’t back down, even when I know you’re scared. But you’re only 17, you
still have a lot of growing to do. I was going to wait, let you grow up a
little, get stronger. The demon’s changed that. I know you can handle whatever
I throw at you, now. You can handle me. If something happens and I lose
control, I know the demon will protect you.”
He sighs and looks away, wondering if he’s explaining this properly, how he
feels, how much the demon has changed things for him. “I’ve wanted you since I
met you. But you were, you still are, young. I’m—damaged, Stiles. I don’t want
to hurt you, if I can help it.”
“He likes you, you know.”  The words draw Derek’s attention back to Stiles, let
him see the way a hesitant smile is starting to curve up those lips.  “He’s not
wild about the idea of sharing me, but …”  There’s a blush riding over his
cheeks now.  “Um.  He’s … contributed sometimes.  When I’ve thought about you. 
And me.  You and me.  You know.”
Derek’s grin is more shark than wolf. “What have you been thinking about?” he
murmurs, sidling closer. “Been thinking about me fucking you? Riding my cock?
Opening yourself up for me while I watch?”
There’s a catch in Stiles’s breath, a stutter that makes Derek’s blood thrum in
satisfaction.
“I’ve thought about that,” Derek goes on.  He’s close enough to feel the heat
of Stiles’s body now; close enough to feel his breath against his face.  He can
feel his control fraying more and more, and for the first time in as long as he
can remember, he doesn’t try to stop it.  “Thought about how you’d look, how
you’d sound.  How you’d smell.”  Derek breathes in deep, exhaling again on a
low rumble that has Stiles’s eyes darkening.  “How you’d feel inside.”
“God,” Stiles can’t help whimpering, eyes sliding closed as the images Derek’s
painting bombard his brain. The demon isn’t helping either, providing graphic
images of how Derek would look under them. Isn’t that a novel idea, he and the
demon sharing Derek, not just Derek and the demon sharing him. His cock
twitches and he bites his lower lip to muffle a groan.
“Stiles.” 
There’s less than a hand’s breadth of space between them now.  Stiles’s scent
is making Derek’s head spin, and he doesn’t know how much longer he can go
without touching him. 
“Say that I can.”  He leans another fraction of an inch closer, until his nose
is just shy of brushing against the fragile skin beneath Stiles’s ear.  “Say
yes.”
Feeling Derek’s breath against his skin shouldn’t make him this hard. “Yes,” he
moans, a nudge from the demon making him dart in and bite Derek’s neck. Not
hard, but not gentle, either. God, the feel of Derek’s skin between his teeth,
against his tongue, makes his head spin, makes his cock leak even more. He
feels like one simple brush against it will make him come in his jeans.
When Derek lets out a sound that’s caught somewhere between a moan and a snarl,
baring his throat to offer better access, Stiles very nearly loses it then and
there.  He’s sick of fighting this, sick of denying what he wants because he’s
just not sure.  The demon in his head is still pushing, still demanding, and
Stiles gives a mental, Oh, fuck it before he fists a hand in Derek’s hair and
yanks his head up to take his mouth in a sudden, bruising kiss.
“Later,” he gasps against Derek’s mouth when he has to pull away to breathe. 
“Later, you’re going to hold me down and fuck me ‘til I’m begging you to stop. 
But now?”  He nips sharply at Derek’s lower lip and takes advantage of his
surprise, giving him a shove with his normal human strength that nevertheless
sends Derek toppling backwards onto the bed.  The wild look in Derek’s eyes is
like a drug as Stiles climbs on top of him, straddling his hips in one swift
move.  “Now you’re gonna lie back and let us do all the work.”
Derek’s hips buck up against Stiles’s weight, grinding his cock against
Stiles’s ass. Part of him thinks that he shouldn’t be letting Stiles push him
around like this, but mostly, he wants to see what Stiles will do. Whether
Stiles can really deliver what he’s promising. “Do it,” he demands, watching
Stiles intently through heavy-lidded eyes. He pushes away the thought that
peeks in from a dark corner of his mind, wondering if it’ll be Stiles or the
demon fucking him. At his point, he doubts it really matters, besides he’s too
turned on to really care.
Stiles is dimly aware of a faint, reasonable voice in his head that’s saying
slow down, too much, too soon, reminding him that he’s never done this before,
that he’s never done anything more than kiss another person before tonight. 
It’s a voice that finds an echo in the slippery, nervous knots in his stomach,
in the way his skin feels hot and cold by turns.  This isn’t just jumping into
the deep end—this is diving head-first into the goddamned ocean, and Stiles
isn’t at all certain that he knows how to swim.
But the demon’s voice is a low, insistent purr; bolts of excitement and desire
sparking through his brain, until he can’t tell which thoughts are his and
which thoughts are the ones his demon wants him to have.  It doesn’t matter, in
the way that it’s never mattered, because the line between them blurred a long
time ago, and it’s all too easy to let anticipation drown out nerves.
When he tears at Derek’s belt his stomach is quaking but his hands are steady,
and the part of him that’s still not certain is washed away in the tide.
Derek can’t help reaching out and touching Stiles, tracing down his sides to
rest at his hips, trying to soothe any doubts that might be lingering. He
watches Stiles as he opens Derek’s belt and jeans. He leans down and nudges
Derek’s shirt out of the way so he can nuzzle the trail of hair disappearing
down into Derek’s boxer briefs. “Any plans yet?” he asks, voice a rough husk at
the feel of Stiles’s breath against his skin. “Gonna suck me down? Gonna ride
my cock? Wanna fuck my mouth?”
“Yes,” Stiles groans, face still buried against Derek’s stomach.  “God, yes,
all of that, I want … I want …” 
The feel of panting breaths against his skin has Derek’s fingers itching with
the urge to manhandle Stiles exactly where he wants him, and he fists them in
the sheets to keep from giving in.  And then his brain shorts out altogether
when Stiles drifts lower, tugging at Derek’s jeans as he moves down to mouth at
the erection tenting the front of Derek’s boxers.
“Stiles, fuck.”  Derek hears the sheets tearing as if at a distance, vaguely
aware that his claws have come up and utterly incapable of caring.
“Yes.”  Stiles pulls up then, straddling Derek’s hips again, and there’s the
press of bare skin against his thighs.  He hadn’t even noticed Stiles shedding
his own pants; Derek thinks that he should probably be concerned by that.  He’s
really, really not.  “Want you to fuck me, Derek,” Stiles breathes against his
mouth.  “Wanna ride you ‘til you’re wild with it, ‘til you’re feral.”
Derek’s hips jolt at Stiles’s words. “Te-tell me you have lube or something,”
he gasps. His breath catches as Stiles leans across him, body pressed tight to
Derek’s, and reaches into the bedside table.
“I’m a teenage boy, of courseI have lube,” Stiles snarks, settling full-length
on top of Derek. His hips are working against Derek’s, their cocks pressed
together sending shivers through both of them. He leans down and licks a swath
up Derek’s neck to nibble his ear.
“Stay still,” Stiles gasps out, tilting his head in invitation when Derek
starts scattering rough, stinging bites across his neck.  “I need you to just …
while I …” 
He leans up again, enough to open the half-empty bottle that he’s pulled out
and coat the fingers of his right hand.  Derek watches in a haze, his vision
turning sharper in the way that means he’s close to shifting, as Stiles reaches
back.  The sound that Derek makes is half-groan, half-snarl; he starts to surge
up, flip Stiles over for a better view, but Stiles’s free hand presses hard
against his clavicle and shoves him back down.
“We said, stay.” 
The demon glares down at him out of jet-black eyes, fingers tightening subtly
around Derek’s throat.  Then he moans, hips shifting back eagerly onto his own
fingers so that his cock brushes Derek’s in a maddening tease.  Those eyes
flutter shut, and when they open again they’re a familiar honey-brown, but the
smile that Stretches Stiles’s lips is sharp and wicked.
“Good boy.”
There’s a whine pushing at Derek’s clenched teeth. He never expected having his
own strength matched would make him this hard. “Stiles, fuck.” He presses up
into the hand against his throat, wishing any bruises would linger longer than
a handful of seconds, wanting to know what they did.
“You like that?” Stiles’s asks and Derek isn’t entirely sure if it’s Stiles
himself asking or the demon, or both of them and that should unsettle him more
than it does. “Like my hand wrapped around your throat, controlling you?”
“Tell me you’re ready or I swear to God I’m going to come on you and not in
you,” Derek growls.
“Yeah.”  Stiles’s breath catches in his throat and he pulls his hand away,
whimpering a little as the shock of sudden emptiness hits him.  “In me, fuck,
yes.”
He’s not ready.  He knows it.  He’d barely gotten started—and Derek’s cock, he
thinks in a daze as he wraps his hand around it to get it good and slick, is a
hell of a lot thicker than two of Stiles’s spindly fingers.  They’re both still
dressed from the waist up, Stiles still isn’t entirely sure of what he’s doing,
and this is going to hurt.  But his limbs are moving almost on their own,
shifting his body forward until he’s braced over Derek’s hips.  Stiles looks
down at eyes that are hazing red, lips pulled back in a snarl over long, sharp
teeth, a brow that seems to be lowering as he watches.
He plunges down, taking Derek inside in one hard thrust, and his scream almost
drowns out the wild roar of satisfaction that rips out of the man beneath him.
“Jesus, Stiles,” Derek gasps, grabbing onto his hips and holding him still
while they both adjust. The scent of blood hits him like a hammer and he’s not
sure where it’s coming from. His wolf whines, pushing against his control,
aching to take and have; knot and breed; to claim what is theirs.
Stiles grits his teeth at the sharp stretch of Derek’s cock in his ass. He
doesn’t thinkhe’s torn anything in there, but it sure hurts. The demon nudges
at him, pushing to take over long enough help ease the pain into pleasure.
‘Pleasure so sweet it aches,’ he purrs, promises.
Derek’s still struggling for control when Stiles begins to move, slow rocks of
his hips as he uses the hand at Derek’s throat for leverage.  It’s good, so
good, warm and slick and tight, as perfect as Derek had imagined it.  Stiles’s
eyes slide half-closed, and beneath the heavy lids Derek can see them shifting,
flickering between gold and black.  It’s as if they’re taking turns, Stiles and
his demon, riding him together at a pace that just grows faster as Stiles’s
body adjusts.  Derek feels sick for the jolt of lust that hits him at the
thought, the knowledge that he’s fucking something evil and beloved all at
once.
“You feel so good.”  Stiles’s mouth has fallen open; he looks lost as his hips
lift and fall, and the harder he moves the more dazed he looks, until his
still-flickering eyes sharpen abruptly as they lock on Derek’s.  “You’d feel
even better with your knot in me.  You want that, don’t you?  I can feel it;
feel how you’re aching for it.  To tie me to you, fill me up.  Pretend that you
can breed this body until it’s swollen with your seed.”  He leans down, swiping
his tongue wetly over Derek’s lips, his teeth.  “And who knows,” he says lowly
before his eyes bleed slowly all the way to black.  “With me in here, who’s to
say you can’t?”
“Stiles!” The wolf roars to the surface, wanting, aching for that: a pack made
of blood, not bites. A snarl curls Derek’s lips as he grabs Stiles’s waist,
braces his feet on the bed and pounds into Stiles’s body. His knot swells
until, with one last hard thrust, it’s locked inside Stiles and Derek’s filling
him with come.
Derek’s eyes are locked with Stiles’s, watching his eyes flicker from black to
molten gold until, with a loud moan, they slide closed and Stiles arches back
over Derek’s knees, streaking his skin with his own come.
They collapse together, filthy and weak and aching, with Derek still locked
inside of him and Stiles’s come drying thick and sticky between their bellies. 
It’s the first time sex has ever actually left him sore, a bone-deep ache that
feels almost as good as it had to come buried deep in Stiles’s body.  Almost as
good as that, but not nearly as good as the feeling of being there still, of
knowing that Stiles is going to smell like him for weeks after this.
The room reeks of sweat and sex, echoing with the sounds of them struggling to
get their breath back.
“Just so you know,” Stiles mutters, the sound muffled against Derek’s shoulder,
“he’s full of shit.  You can’t actually get me pregnant, demon or no.”
Derek’s laugh is long and loud.
Stiles smiles smugly to himself against Derek’s shoulder even as aftershocks
tremble through him caused by the movement from Derek’s laughter. “You should
do that more often,” he murmurs, propping his arms on Derek’s chest so he can
see his eyes.
Derek hums questioningly, all but purring from contentment.
“Laugh,” Stiles explains as he reaches up and traces Derek’s lower lip with his
thumb. “You don’t laugh enough.”
With a nip at Stiles’s thumb, Derek opens his eyes and meets Stiles’s gaze.
“Good thing I’m keeping you, then.”
Stiles buries his face in the side of Derek’s neck, letting himself hope for
the first time since he first saw Derek Hale appear in the woods.
“It’s a package deal, you know.  Me and him.”  He wishes they were having this
conversation later, when he isn’t tied to Derek like this, when he could get up
and away if the answer is a bad one.  “Are you sure—”
“Stiles.”  A hand slides down his spine, curling around his ass to tug him even
closer.  “Both of you.  Shut up.  You’re gonna need your rest if you wanna go a
second round.”
“Asshole,” Stiles mutters, but he’s smiling as he settles in, wrapped in
possessiveness and affection both within and without.
End Notes
     If you want to see ridiculous things like this happen in real time,
     you should follow us on Tumblr! Our usernames there is
     hungrylikethewolfie and umbralillium, and things are only this porny,
     like, 95% of the time.
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