He wakes up before dawn on Christmas morning, rolling stealthily out of bed and leaving her tucked up and dreaming.
Shrugging into a bathrobe against the chill, he carefully closes the door behind himself, so as not to wake her, and goes to turn on the Christmas lights so they'll already be on when she gets up. He's never missed a year of lighting it for her before this, and he's not about to start off this first year in their new apartment without it.
There aren't many presents under the tree; they'd agreed, a week ago when they'd signed their names to the lease, that moving in together was enough of a present for anyone. But they had decorated it the night before with a mix of old ornaments and new, tinsel, lights and garland; once he plugs in the cord, despite the lack of boxes beneath it, everything looks just right - and not only because it's theirs.
He stands and watches it for a few moments, smiling at the flutter of excitement in his stomach at the thought of her happy face, then forces himself to turn away and head for the kitchen. There's one more tradition left to take care of: they may not be at home anymore, but he can surely manage a batch of Mom's chocolate chip breakfast muffins on his own.
The ingredients are hidden carefully in the fridge behind the roast for Christmas dinner (as surprise presents are the best kind) and he assembles them quickly: oranges, sugar, flour, chocolate... it's been a while since he helped make muffins, but he remembers it all without needing a recipe. This is the sort of thing that's like riding a bicycle. Or - almost, because he realizes, after he's already got the batter mixed and poured into the tins, that he's forgotten to preheat the oven. It's not really a big deal, because it'll give him time to clean up and start the coffee, but he still smiles ruefully at his own overconfidence.
Dishes in the sink, muffins (finally) in the oven, mugs on the counter. He leans over the coffee machine, closing his eyes to take a deep breath of steam (pine needles, sugar, coffee - amazing) and nearly jumps out of his skin when her arms slip around his waist with no warning.
"Sister," she reminds him cheekily, as if he might have mistaken her for someone else. She presses close to his back for warmth: her arms are bare where they wrap around him. She's probably still in the teddy she'd come to bed in the night before, he thinks, skimpy-cut crimson silk and white trim (this is Christmas, she'd said when she tried it on for him, though before now he'd never understood the appeal of Mrs. Santa.)
Her right hand flattens against his stomach, untying his bathrobe and sliding under his shirt to find his bare skin. Her fingers are chilly - how long has she been out of bed? - but when he shivers it's not from the temperature.
"Good morning," he says, breathless, and almost like a reward her hand dips down into his shorts, the side of it trailing against the hot, hard flesh of his cock. He grabs for the edge of the counter to keep his balance and she giggles against his shoulderblade, brushing him with that barely-there touch one more time.
For an instant he thinks she means to keep teasing, but before he can finish the thought she twists her hand and he slips into her palm, sliding slick with precome already against that perfect smooth skin. His breath stutters as she cups him, a gentle squeeze, a firm stroke, her other arm still around his waist like she's holding him upright.
"You weren't in bed when I woke up," she says, tugging his shorts down just enough that she can pull his cock free, pump him faster, and he can only answer with a moan.
She laughs at him again - and then again, when she lets go of his dick and he makes a wordless noise of protest. But she's putting her hands on his hips, turning him around to face her, and God, but she's beautiful, sleep-mussed, her nipples stiff points through the teddy in the chill morning.
When she leans up to kiss him, his cock slides against her sleek, silk-covered belly with a jerk that almost undoes him. "Please," he says, letting her lip slide from between his teeth full and pink.
But she doesn't reach down for him again - she just gives him that low, promising look that's been undoing him for years and drops to her knees. She turns her cheek against his cock; her hot breath, the cold air, the brush of her hair as she bows her head: he moans again.
She licks first at the base of his cock, then at his balls as she cradles them in her hand, tiny laps that are more a promise than a fulfillment. He wants more, wants her mouth on him so badly he can't stand it, wants to slide over her tongue, between guarded teeth, wants to see those lips he's just kissed stretch wide around his cock.
Thank god, she doesn't make him wait much longer; just as he thinks he can't stand it a second more, she sucks him down and looks up to meet his eyes at the same moment.
He touches her mouth, traces her lips - she swirls her tongue around him as he does, following the path of his fingertip, and he trembles, locking his knees and leaning heavily back against the counter. She leans in, taking more and more in one smooth glide until she's nuzzled up against him, lips still working over him, and she swallows.
It shoots through him like lightning, crackling along raw nerves, and he says "God, sis, I'm --" and she does it again. The way her throat moves around him, the feel of her breasts pressed against his thigh - he can't hold back a second longer. His warning turns into a choked gasp and he's coming, pouring it down her throat in desperate pulses as she sucks and sucks.
Her hands creep up the back of his thighs, pulling him to her as if she can't be close enough to him, and his hands are on her face again, stroking her cheeks, her ears, the curve of her jaw, anything he can reach as he comes down from the high. She lets go just as it's starting to be too much, lets his cock slip back out of her mouth. Her lips are wet, swollen from more than kissing now, and she is so perfect it makes his heart ache.
He lets his hands fall from her face to her shoulders, pulling her up to him to kiss her again - the faintest taste of salt on her lips - and hold her close for just a moment. She really is cold, and with a flicker of guilt he tugs up his shorts, shrugs out of his robe and swings it around her shoulders, then impulsively picks her right up and hoists her onto the edge of the kitchen counter as she half-shrieks in surprise.
"No, what are you doing?" she asks, laughing, but he just grins and steps forward in reply, nudging her legs apart so he fits between them. When he kneels down in front of her, kisses her just above the knee where she's ticklish, she shivers deliciously and splays out wider, letting his robe gape open and sliding one leg up over his shoulder, slanted over his back, drawing him closer again.
She's not wearing underwear - he has a vague memory of the panties that match the teddy flying, elastic-shot, across the bedroom the night before - and so he kisses a long, unbroken line up her thigh as she draws him in, feathering the last one over her clit. When he licks down he finds her unbelievably wet already, his tongue sliding easily between plumped lips and inside as far as he can get.
Her hand is in his hair almost immediately, holding him there so she can rock her hips against his face, her clit rubbing the bridge of his nose as she fucks herself on his tongue. "Yes," she hisses, a long breath that shudders into a whimper when he brings up his fingers, thrusts two suddenly, deeply inside her, slides back upwards against her slick cunt to focus on her clit, tonguing it with the stiff vibrating flicks she loves when she's about to come for him.
Her other leg joins the first over his shoulders, hand tightening in his hair, and she rocks harder, kicking him almost-gently in the back when he's not quite fast enough for her.
He can't breathe but doesn't care; crooking and rubbing his fingers up inside of her, he licks faster until she gives that sweet little gasping cry, though her thighs are so tight against his ears that he can barely hear it. Her pussy ripples around his fingers and he pushes in a third before she's done, stretching her wide and tight around them, his tongue slowing on her clit; broad, soft licks now, just enough to carry her through it.
When it gets to be too much for her, she unhooks her legs, pushes his head away gently; he lets his fingers slide slick out of her, wipes his face on her her thigh and his hand on the bathrobe (she giggles and smacks him, her breathing still fast and unsteady).
He's about to stand when the shrill beep of the oven's alarm brings him to his feet faster than he'd intended to rise, sending him stumbling into her; she catches him, steadies him, then slides down off the counter with a long, satisfied stretch.
She sniffs the air (it mostly smells like sex now, although the Folgers and the oven are putting up a decent fight) and slides her hands into his. "Do I smell Mom's muffins?" she asks, eyes crinkling as she smiles: she already knows the answer.
"Merry Christmas," he says, bending down for a quick peck of a kiss before going to rescue the muffins.
They're perfectly done, sugar browned crisp at the edges into a hint of caramel to accent the chocolate; he turns them out onto a plate, almost but not quite burning his fingers, as she pours two mugs of coffee.
"Let's sit by the tree for a while," she says, waving the mugs at him and heading over into the other room. He smiles after her and goes to get her bathrobe, slinging it over his own shoulders before retrieving the muffins and following her to the couch in front of the tree.
The sun will rise soon enough, and soon enough he'll have to tidy up their bedroom and put dinner on while she musses the bed she doesn't sleep in and checks over everything else before their parents arrive. He settles down, trades her a muffin for a mug; she leans into him with a quiet, sated sigh and he slips his arm around her, resting his head on hers. They still have a little time before then to be just themselves.
And they'll have their whole lives, after.