Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/
works/1498039.
  Rating:
      Explicit
  Archive Warning:
      Underage
  Category:
      M/M
  Fandom:
      Teen_Wolf_(TV)
  Relationship:
      Stiles_Stilinski/Stuart_Stilinski, Derek_Hale/Stiles_Stilinski/Stuart
      Stilinski, Derek_Hale/Stiles_Stilinski, Derek_Hale/Stuart_Stilinski
  Character:
      Stiles_Stilinski, Derek_Hale, Stuart_Stilinski
  Additional Tags:
      Twincest, Incest, Unsafe_Sex, Barebacking, Anal_Sex, Threesome, set_after
      3b
  Stats:
      Published: 2014-04-21 Chapters: 1/? Words: 3429
****** Twice the Fun ******
by sisforsterek
Summary
     Stiles needs a ride to the airport to pick up his twin. Derek's
     certain Stiles has never told him that he has a twin. He agrees and
     things get interesting from there.
Notes
     Regarding the Malia hookup, in this verse, all Stiles and Malia did
     is what was shown on TV. They made out. Stiles is still technically a
     virgin.
     I've recently fallen in love with the idea of Stuart as Stiles' twin,
     so I took a little break from my Sterek mpreg to write this. It will
     have additional chapters.
"Say that again," Derek says.
"I need a ride to the airport to pick up my brother. My Jeep's in the shop, Dad
has to work, and no one else can take me," Stiles says.
"You have a brother," Derek says giving Stiles a disbelieving look.
Stiles nods.
"That you've never mentioned," Derek continues.
"Surely I have," Stiles says.
Derek shakes his head, "You haven't. Trust me. I'd remember."
"So will you take me?" Stiles asks.
Derek nods.
"So how old is your brother?" Derek asks once they're in the car.
"My age. We're identical twins," Stiles replies.
"There's two of you?" Derek says, voice going up in pitch.
"Yep," Stiles replies with a smirk.
Derek groans.
"His name is Stuart," Stiles continues. "He's a computer genius. He developed a
program that even I don't understand when he was 14 and Microsoft bought it. He
ended up getting into MIT when he was 15 and this is the first time he's been
home in two years. Dad and I usually go out to see him every few months, but he
decided to take this summer off from college to come home, you know, after what
happened."
"Does he know about werewolves then?" Derek asks.
"Yeah, and kanimas and darachs and kitsunes and nogitsunes. I tell him
everything. We don't keep secrets," Stiles answers.
"So wait, you get a name that is impossible to pronounce and his name is
Stuart?" Derek asks.
Stiles laughs. "I'm firstborn. I got the family name from Mom's grandfather and
Stu was named after Dad's side of the family."
"So he's smarter than you, huh?" Derek asks.
"I wouldn't say smarter. He just doesn't have ADD, so he's more focused and has
different interests," Stiles answers.
"You always act like your dad is all you have, so I'm just shocked to find out
you've got a brother," Derek says.
"That's because I knew Stu was safe at MIT away from this mess," Stiles
answers.
"I'm sure there are things that go bump in the night at MIT too," Derek adds.
"But Stu isn't like me. He doesn't go looking for trouble."
"Good to know at least one of you has sense," Derek says.
"Hey!" Stiles protests.
Derek thinks for a minute.
“You don’t have a third bedroom,” Derek says.
“Right,” Stiles agrees.
“So where did Stuart sleep before he left for MIT?” Derek asks.
“You’re really having a hard time wrapping your head around this, aren’t you?”
Stiles asks with a laugh.
Derek glares at him.
“My room used to be our room,” Stiles explains.
“But you only have one bed,” Derek points out.
“And you would know, since you seem to love hanging out in my room,” Stiles
adds.
“So where does he sleep?” Derek asks when Stiles doesn’t elaborate.
Stiles sighs. “We used to have separate beds, but we’d always end up crawling
into each other’s beds after Mom died, so finally dad just got us a double, and
we shared a bed for years until he left.”
 
Derek isn't sure what to expect while he sits next to a fidgeting Stiles while
waiting for his brother to meet them at baggage claim. Stuart had already
texted Stiles when his plane had landed.
Suddenly Stiles jumps out of his seat and runs toward the area with the moving
luggage belt. Derek looks up to see him wrap his arms around what is basically
his mirror image except for a pair of black rimmed glasses. Stuart hugs Stiles
back as Derek gets up to make his way toward them. As he approaches and they
finally pull apart, only to have Stiles drape his arm over the back of Stuart's
shoulders, Derek can see that Stuart is thinner, more like Stiles was before he
started running with werewolves.
Stiles is talking a mile a minute, gesturing with the hand not on Stuart's
shoulder, and Stuart is looking at Stiles with obvious affection. Derek can
tell they obviously have a closer relationship than many other siblings he's
observed.
Finally Stuart looks away from Stiles and glances at Derek.
"You must be Derek," he says. "Stiles has told me quite a bit about you." Then
directed at Stiles with a smirk, "I see what you mean."
His voice is slightly deeper than Stiles' but otherwise they even sound alike.
It's messing with Derek's head to see this other version of Stiles. It's like
he's never noticed before just how attractive he is. Then immediately he feels
guilty. Stiles is a kid!
By the time Stuart has his luggage, Stiles has convinced Derek to take them to
a restaurant, because Stuart is hungry and Stiles is always hungry. Derek
agrees, not like he had anything important to do today. They end up stopping at
TGIF’s and are escorted to a booth. Stiles and Stuart take one side of the
booth while Derek slides into the other side.
“So what’s new?” Stiles asks, bumping his shoulder against Stuart.
“Literally nothing since we Skyped this morning,” Stuart replies.
“What? Nothing interesting happened on your trip?” Stiles asks incredulously.
Stuart shakes his head.
“You had your nose in a book all day, didn’t you?” Stiles asks with a laugh.
Stuart shrugs his shoulders, “The graphic novel you gave me for our birthday. I
finally have time to read it. I like it.”
Stiles face lights up. “Well at least it’s not a textbook.”
Just then the waitress shows up with their menus and takes their drink orders.
They’re mostly silent for a few moments while they decide what they want. As
soon as they’ve placed their orders though, Derek can’t hold his curiosity back
any longer.
“So what are you majoring in, Stuart?”
“Double major actually. Aerospace engineering and computer science and
engineering,” Stuart answers.
“He wants to work for NASA,” Stiles adds, and the look he’s giving Stuart hides
nothing. He’s obviously proud of his brother.
“But if that backfires, I’ll be the next Steve Jobs,” Stuart says.
“Steve Jobs? I thought Stiles told me that you sold your program to Microsoft?”
Derek says, obviously confused.
“I was fourteen! I’ve learned a lot since then and I’m more of an Apple guy
now,” Stuart says with a chuckle.
“You know the difference between Bill Gates and Steve Jobs?” Stiles asks.
“I do watch the news,” Derek says with a laugh.
“Huh.” Stiles says.
“So do you have a girlfriend back at MIT?” Derek asks.
“Uh, I’m gay actually, but I don’t have a boyfriend either,” Stuart answers,
glancing at Stiles.
When the food arrives, Stiles and Stuart immediately start stealing food from
each other’s plates. Derek knows if anyone else would try that, Stiles would
stab them with his fork. He’s seen him do it to Scott before. Halfway through
the meal, Stiles even drinks from Stuart’s cup after he empties his own before
the waitress has come by to offer a refill. Derek never had that kind of
relationship with his siblings, but it still makes his chest ache in the worst
way watching the two boys across the table from him laugh and communicate
through gestures like they share their own secret language.
Because they’re teenage boys and eat like them, they have to order dessert.
Stiles orders the Chocolate Peanut Butter Pie and Stuart orders the Vanilla
Bean Cheesecake. Of course they have to share that too. And if that’s not
enough, Stuart lets out little sighs of pleasure each time he takes a bite and
the moans that slip out of Stiles’ mouth are bordering on obscene. It’s making
Derek uncomfortable. Watching two teenagers eat should not be causing the
reaction that’s currently going on in his pants. He shifts uncomfortably in the
booth.
“Want a bite?” Stiles offers.
“I’m good,” Derek manages to say through gritted teeth.
After he helps carry Stuart’s bags inside the house, he doesn’t see a reason to
stick around, so heads back to his car. He pauses upon hearing a thump come
from inside the Stilinski house, followed by a gasp, and then a groan. He runs
back to the front door and peeks inside the window. What he sees is not what
he’s expecting. Although neither twin is in danger, what he’s seeing is still
wrong. Stiles is straddling Stuart on the couch and the twins are kissing.
Stuart’s hands are tugging at Stiles’ hair and Stiles is grinding down against
his twin. Derek backs away in shock.
Derek spends the next few hours back at his loft switching between pacing the
floor and sitting on his bed staring at the wall. He can’t get what he saw out
of his head. It’s so wrong, but it was really, really turning him on the more
he thought about it. He’d never really thought about other men in a sexual way
before. He’d been taken advantage of one too many times in the past to really
consider sexual relationships in general for the most part. But this was
Stiles, someone he trusted. He’d certainly noticed the way Stiles looked at him
sometimes, the scent of arousal coming off of him in waves when Derek would
push him around sometimes out of frustration and sometimes for his own safety.
Derek had refused to think about what that meant. Stiles is a teenager who
probably got off on any sort of physical contact.
Before Derek realizes what he’s doing, he’s in his car, driving to Stiles’
house. His dashboard clock reads 11:37PM. He shuts off the engine and takes a
deep breath. Stiles will still be awake. It’s summer break. His dad, on the
other hand, should be a sleep, so he decides to use his normal entrance,
Stiles’ bedroom window. There’s a lamp on in Stiles’ room, and Derek can hear
Stiles and Stuart whispering, but he can’t make out the words from where he’s
standing in the yard. When he slides the window open, he hears someone gasp out
“Who’s there?”
“It’s me,” Derek says as he slides through the window, feet touching down on
the floor. When he glances around the room, he notices two sets of eyes staring
at him from Stiles’ bed. Stiles and Stuart are staring at him from the bed,
both shirtless with the sheet coming up to their waists, their hair sticking
every which way and their lips red and swollen. Derek can hear their hearts
racing and he can smell the scent of arousal in the air. Derek realizes what
he’s just walked in on. His eyes widen.
“Is something wrong?” Stiles finally asks.
“I… I don’t know why I’m here,” Derek admits, eyes darting around the room. “I
saw, earlier, when I dropped you off, I heard something, so I came back, and I
saw, on the couch…”
“Oh my God,” Stiles moans, turning to rest his head on Stuart’s shoulder.
Stuart seems unaffected. He just stares at Derek for a minute.
“Do you want to join us?” Stuart asks.
"Oh my God," Stiles says again.
"What? He's your wet dream," Stuart whispers.
"Werewolf hearing!" Stiles whispers back.
"Sorry." Stuart says as he rubs his hand along Stiles' back. Then he looks back
to Derek, "Well?"
"You're underage," Derek says, clearing his throat.
"Combine our ages and we're 34, totally legal," Stuart says. It’s such a Stiles
thing to say.
Stiles snorts and pulls back from Stuart to send Derek a hopeful glance.
Derek nods. He can’t believe he’s giving in this easily, but he knows this is
the reason he came here, "How's this going to work?"
"Start by taking your clothes off," Stiles says.
Derek wastes no time stripping, trying not to think about how wrong and illegal
this is. Once he's naked, he looks up. Stiles is staring at his cock,
completely unashamed. Stuart is leaning against Stiles with his head resting on
his shoulder, eyes pointing in the same direction.
"Now get on the bed," Stuart instructs.
Derek takes a step forward, unsure all of the sudden, "I've never been with a
guy before."
"It's okay," Stiles says, "we're technically virgins."
"But-" Derek starts.
"We just fool around with each other. We've never went all the way," Stuart
explains.
Derek lets out a breath, feeling better knowing at least he doesn't have to
live up their previous experiences. He finally sits on the edge of the bed next
to Stiles. He looks at Stiles and waits.
“What do you want to do?” Stiles asks shyly.
“What do you want to do?” Derek asks, thrown by the question because Stiles is
anything but shy.
“Um,” Stiles starts, but doesn’t actually answer the question, instead he looks
at Stuart for some reason.
Stuart lets out a breath and rolls his eyes, “He wants you to fuck him.”
“If you want to,” Stiles adds quickly.
“Ok, yeah,” Derek agrees, then turns to Stuart, “What about you?”
“You can fuck me too after, or if you want, I can fuck you while you’re fucking
him. I’m so cool either way,” Stuart replies.
Derek really isn’t sure what is hotter, the shy looks Stiles keeps shooting at
him or the confident way that Stuart is telling him what he wants. He’s also
never even thought about letting a guy fuck him before, but the idea of fucking
Stiles while Stuart fucks into him is just too good to pass up.
“The second option’s good,” Derek says. “So…”
“I can get him ready for you, if you want,” Stuart says, gesturing to Stiles.
“I know how he likes it.”
Derek thinks he’s going to blow his load before he even gets his dick in
Stiles, but he nods. He watches as Stiles turns over and props himself up on
his hands and knees. Stuart finds a bottle of lube that must have been hidden
under the sheets. He glances down Stiles back while Stuart coats his fingers,
noticing a mole right at the top of his right cheek. Derek wants to bend down
and lick it, but he waits. He watches as Stuart spreads Stiles’ cheeks apart
and rubs a slick finger around the rim of his hole. Stiles shifts forward
slightly on the bed and lets out a whimper. Derek grips the base of his cock to
keep from coming at the sound. He watches, trying to memorize every move Stuart
makes, so he can do it himself if he gets the chance in the future. He hopes
this won’t be a one time thing. He observes how Stuart uses one hand to stroke
the curve of Stiles’ spine while he thrusts his fingers into Stiles’ hole with
the other hand. He watches as Stiles rocks his hips back to meet the hand.
Suddenly Stuart’s hand is on Derek’s cock and he gives it a few strokes before
pulling away.
“I think I’m going to have to add another finger, bro,” he says.
And Derek watches him add a fourth finger and waits for Stiles to adjust.
Stuart leans down and kisses his shoulder while he waits, then turns to Derek.
“You can touch him, you know,” he says.
Derek had been enjoying watching so much, he kind of forgot he could
participate. Now that he’d been reminded, he couldn’t decide what to do first.
He reaches out a hand and caresses Stiles’ hip, letting it slide down his leg
and rub the inside of his knee. Stiles turns his head and meets his eyes,
giving him a soft smile. Then Stuart is back to thrusting his fingers into
Stiles’ hole and Derek gets a bit braver. He moves up the bed and leans down to
kiss Stiles. At first it’s closed-mouthed, but then Stiles starts to moan and
Derek slips his tongue inside. All too soon Stiles pulls away, but he is
smiling.
“I’m ready,” he says.
Derek moves back behind Stiles.
“Condom?” Derek asks.
“Well, you can’t get me pregnant, and I know werewolves don’t carry STD’s, so
you don’t have to use one,” Stiles says.
“Okay,” Derek says and then Stuarts hand is on his cock again, this time
slicking him up with lube.
Then Stuart is pulling his fingers out of Stiles and Stiles lets out this
pathetic whimper that has Derek wanting to do whatever he can to make him
happy. Stuart is whispering in his ear, telling him to push in slowly, before
he’s gone again and then Derek does as he’s told. Derek is about halfway in
when he feels the bed shift behind him and Stuart’s hands on his hips. He’d
been focusing on not hurting Stiles, so he’s surprised when he hears Stuart say
that he’s going to prepare him now. He tries to relax as he feels a finger rub
across his hole. He continues to push into Stiles as a slender finger slips
into him. It doesn’t hurt, but it’s an unusual feeling. He’d never had the
desire to finger himself before, but with the way Stiles seemed to enjoy it,
he’s kind of looking forward to the experience. Just as he’s bottoming out into
Stiles, Stuart curls his finger inside of him and hits a spot inside of Derek
that makes his hips spasm.
“There it is,” Stuart says and slides in another finger. Then Stuart’s
whispering in his ear again, “Reach under him and grab his cock, give him a few
strokes while he adjusts to you inside of him. He’ll let you know when he’s
ready for you to move.”
Derek does as he’s told, but turns his head to whisper back, “How do you know?”
“Porn, dude. Stiles and I watch a lot of porn.”
Stiles says he’s ready just as Stuart’s slipping another finger into Derek.
It’s almost too much to focus on all of the sensations, but he tries to tune
out what Stuart is doing for the time being to focus on not hurting Stiles. He
pulls back slowly and pushes back just as slowly. He does it a few more times
before Stiles starts pushing back.
“Yeah,” Stiles says. “Come on.”
Derek takes that as a good sign and moves a little faster. Then he feels Stuart
pushing into him. It’s definitely bigger than what his fingers prepared him
for, but it’s more uncomfortable than painful, so he keeps his focus on Stiles.
Stiles is now uttering a constant string of “Yes, please, come on, Derek, don’t
stop.” He’s not shy anymore.
Once Stuart is pushed all the way in, he runs his hands over Derek’s back,
waiting for him to adjust. “You can move,” Derek tells him. He’s back to
focusing on pounding into Stiles who has started to beg for him to go faster,
when Stuart suddenly bites into his shoulder. He had to shift his position to
do it, and when he did, he nailed Derek’s prostate. Stuart continues to hit his
prostate for the next few thrusts and Derek can feel his orgasm building. He
reaches around Stiles to grab his cock again, wanting to make sure he comes
before Derek. He doesn’t have to worry, because it only takes a few strokes
before Stiles is coming. He bites into his pillow to quiet his screams. Derek
follows soon after, practically falling on top of Stiles, barely catching
himself to rest on his elbows to avoid crushing the boy.
After a few moments Stiles manages to turn over underneath him, which causes
his cock to slip out, and he just grins at Derek. Derek can’t help but smile
back and Stiles leans up and catches his lips. Then Stuart is coming and
collapsing on top of Derek, not at all worried about crushing him. They stay
like that for a few minutes before Stuart slowly pulls out and moves to the
side. Stiles turns to look at his brother and smiles. Stuart leans in and
kisses him. Derek feels an ache in his chest and he’s not quite sure what it
means. After a few more minutes pass with everyone reeling in the afterglow,
Derek moves off of Stiles and starts to get dressed. Stiles frowns at him.
“I don’t want to fall asleep here, you know, in case your dad wakes up and
finds me in your bed, not a good idea,” Derek tells him.
“Yeah, probably not,” Stiles agrees, still frowning.
“I’ll talk to you tomorrow, though?” Derek says.
Stiles nods as he turns onto his side facing towards Derek. Stuart cuddles up
behind him and throws his arm over his chest.
“Love you, Stu.” Derek hears just as he’s closing the window. “Love you too,
Stiles.”
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