#singlecellorganisms

Right now is one of those times. He's sitting in English class, trying to pay attention to what Ms. Blake is saying, when his phone buzzes. And he knows -- fucking knows -- that he's supposed to turn it off as soon as he walks through the door but lately, he's been keeping on. For 'just in case' scenarios and emergencies.

And pictures of Cora from the chest down, with Derek's head between her legs does not fall under the category of emergencies. Hell, it doesn't even fit under the 'just in case' one, either, but Stiles can't help but stare at the screen.

"Stiles." Jennifer's voice is stern and loud, right next to him and oh shit.

Fumbling with the lock button, Stiles' heart jumps in his chest and he breathes hard, his hands shaking as he shoves the phone between his legs. Amber eyes sweep up, locking on the sweet face of his English teacher, and she just smiles at him, though he can read her facial expression well enough to know that she's pissed.

"Hmm?"

"I wanted to hear your theory about the book," Jennifer says, in that sickly sweet voice of hers, and Stiles prays that his phone doesn't vibrate against his dick. Prays.

Stiles swallows and shrugs. "I read it in freshman year," he says and 'it' refers to Great Expectations, "and I thought it was a good book."

That's clearly not the answer Ms. Blake wants and she purses her lips before moving onto the next person. It's not Stiles' fault, not really, because all of the blood in his brain has migrated south. Deep south.

When the bell rings at the end of the day, signalling that they're all free from the torture of Math and English and Science, Stiles jumps into the Jeep before Scott and Isaac can catch up to him. Which is a stupid thought, he realizes, because they're werewolves. They could walk briskly and still catch his Baby.

But they don't. They wave to him from where the bikes are parked, though, and Stiles barely has time to return the gesture before he's pushing down on the clutch and shifting into gear.

Stiles' phone buzzes the whole way to the loft. He doesn't check it until he's at a stop sign and then he wishes that he hadn't picked the damn thing up because right there on the screen is a picture of Derek and Cora. They're both naked and laying on the bed; Cora's got her head on Derek's chest, smirking at the camera.

Oh, god. Stiles is so fucked.

Once the traffic is gone (and it's been clear for a full minute; Stiles has just been too preoccupied with the picture to check), he puts his phone down and starts driving again, doing just above the speed limit. It's not enough to warrant being pulled over, so Stiles isn't worried about one of his father's deputies giving him a ticket and seeing the tent in his pants.

It takes fifteen minutes to get to Derek's place. Fifteen long, agonizing minutes before he's pulling in beside the Toyota that Stiles still isn't used to seeing in place of the sleek, black Camaro.

Whatever; cars are the last thing on his mind.

Stiles parks, shuts the car off, and hops out, leaving his book bag on the passenger side floorboard because there is no way he's going to have time to do homework. Not until he gets home and even then, Stiles is almost certain he's going to be too tired and sore to move a muscle.

The thought sends a shiver down his spine and he runs up the stairs, nearly tripping over his own two feet on the final staircase. He regains his balance, shakes himself out, and walks calmly to the loft. 

Does he knock? Does he walk in and throw his clothes off, demanding to be taken and to be taken now? Stiles never knows the protocol, even if Derek tells him to just come on in. It still feels weird, though, like he's barging in on their alone time together, even though he knows he should be in the middle of it.

So Stiles opts for just walking in. If the alarm goes off, well then it goes off and so be it; Stiles is far too turned on to really give a shit at this point. 

The door to the loft slides open, creaking a little from how old the building is and possibly from lack of oiling, and Stiles steps inside. He lets the door slide shut behind him and notes that the alarm hasn't gone off; Derek must have turned it off before he got there.

"Stiles," Cora moans and the teen turns his head to look at her, his eyes widening and his mouth falling open on a moan. Because there she is, sitting stark naked on top of Derek, his head buried between her breasts and one hand between her legs. "C'mere."

Stiles doesn't need to be told twice. He walks over, shedding his jacket and throwing it somewhere onto the floor, toeing out of his sneakers next. They get kicked away and Stiles is started to get hard again, the denim of his jeans becoming unbearably tight.

Once he's standing beside the bed, Derek looks up at Stiles and grins, his hazel irises rimmed in red. That makes the boy moan and he shudders, knees buckling a little but he manages, by some freaking miracle, to keep upright.

"What took you so long?" Derek asks before going back to what he was doing before, which was biting and sucking on Cora's nipples.

Stiles twitches.

"I was at school," he answers and undoes his jeans, shoving them down as he sighs in sweet, sweet relief. "You know, some of us do have lives outside of fucking our siblings."

Cora snorts, then moans loudly.

"Oh my god." Stiles breathes in and out steadily, hands shaking as he fumbles with the hem of his shirt, tugging it up and over his head. He drops the fabric onto the floor, runs a hand along the front of his boxers, where his cock is curved and straining against the cotton. 

"You gonna join us?" Cora's voice is breathless and she squeals, hips moving in a circle against Derek's hand. Stiles can barely hear the Alpha's fingers going in and gulps, nodding automatically.

Stiles moves onto the bed, sitting beside Derek so he can watch what the other man is doing. He's got a hand on the front of his boxers again, stroking himself through the now damp fabric, sucking in a sharp breath with each loud noise Cora makes.

It takes a few minutes for Cora to come. Derek slows his hand down and she whines, tells him that he's an asshole for doing that, and her brother just laughs, the noise rumbling deep in his chest. Then he starts to finger her harder, his thumb working relentlessly against her clit, and Stiles thinks he could come from watching this.

Then she comes. Cora shouts Derek's name, her hips stuttering against his hand as her own bury in his hair, tugging and twisting those perfect, dark locks between her fingers. She's shaking, vibrating with the aftershocks, and when Derek sucks on her nipple, she makes a strangled noise that's something like a moan and a groan and a whine all mixed into one.

"Fuck," Stiles breathes. He's been watching, transfixed, for a while and only moves his eyes away from Cora's body when she climbs off Derek's lap. Then he looks at the Alpha, dropping his eyes down to look at the wetness on his fingers, and Stiles groans.

Derek raises a brow and grins, bringing his hand up. "Want a taste?"

Stiles doesn't even answer. He wraps long, slender fingers around the older man's wrist and brings his hand closer, mouth watering. Then he sucks the digits -- all three of them -- into his mouth, eyes fluttering shut as Cora's taste hits his tongue and he sucks eagerly.

Both of the werewolves moan, causing the boy to blush. He loves when he can affect them both like this, loves when Derek allows him to clean up after Cora. It's honestly, hands down, one of Stiles' favourite things.

"Okay," Derek laughs, breathless. "That's enough."

A whine rises from Stiles' throat when Derek pulls his fingers out and he pouts, his lips slick with spit and Cora's juices. "I wasn't done," he mutters in protest.

"Oh?"  Stiles shakes his head and Derek grins. "So you want to keep sucking on my fingers instead of fucking my sister?"

Well, when Derek puts it like that...