I wake up from a dreamless sleep, my eyes opening to meet the familiar sight of my bedroom ceiling. The curtains are drawn shut, but I can see a sliver of the outside world peeking through. The sun is beginning to slowly peek over the horizon, and the faint golden rays, the sky a hazy mix of various shades of blue. I can hear birds chirping outside, and I glance over at my alarm clock to see the time. 5:23. Damn. 
I sigh and roll onto my back, gazing up at the dark, painted plaster ceiling. My eyelids droop with exhaustion. Why do I just randomly wake up early in the morning sometimes? There's gotta be a name for this phenomenon. Well, whatever it is, it definitely isn't healthy, but it is kinda cool to be awake at a time you know nobody else is up yet. 
The peacefulness of being woken up by birdsong fades away quickly, and now I want to go back to bed. It's Saturday, though. There's still plenty of time for me to sleep. One thing I've never done before in times like this is go to someone else's room. I occasionally go to the kitchen for a glass of water, or go to the bathroom to pee, but otherwise I stay out of everyone else's space. Come to think of it, I don't remember the last time I've seen my sister sleeping. It sounds like such a weird thought, but I really can't recall the last time we were both in the same room, and she happened to be asleep. Well, my curiosity is piqued now. If I'm gonna go snoop around in someone else's room, it might as well be hers.
I push my blanket off of me and slip off the bed, tiptoeing quietly over to the door, entering the hallway. The wooden floorboards creak under my paws, despite how much effort I'm putting into being completely silent. This doesn't instill a lot of confidence in me, but I keep going anyway. I cautiously creep towards Mia’s door, slowly and carefully turning the knob and sliding the door open. My gaze immediately falls onto her bed, and I gasp quietly at the sight. She's holding her phone up in front of her face, and is clearly far from a state of sleep. I freeze as she glances at me in surprise, her eyes widening when she realizes someone else is awake.
"Mike?" she murmurs, lowering her phone. "What the hell are you doing here?"
Her voice is soft, barely above a whisper. I'm still caught in shock at her presence.
"Mia.. You're awake," I point out awkwardly.
"I am," her reply is short, almost curt. 
I bite the bullet and walk towards her bed, sitting down beside her. She looks over at me questioningly, giving me the chance to explain myself if I'd like. The awkwardness seems to hang in the air between us, causing an uncomfortable, tense silence to descend upon us.
"It's five o'clock," I begin. "I just woke up randomly like a few minutes ago, and I was wondering if you were still up."
Mia stares at me blankly for a brief second, then nods slowly.
"Yeah, I...I guess I am still awake," she replies hesitantly. "I actually haven't gone to sleep yet..."
"Oh, wow," I say. "Happens to the best of us. Sometimes I stay up until four in the morning scrolling through social media because there's so much stuff that I feel like I have to check out before sleeping. We rarely get to spend time together like this. Do you mind if I hang out with you for a little bit?"
Mia remains silent. I look over at her hopefully, hoping to see some sort of sign to suggest I should leave, or maybe just some kind of acknowledgement that I'm welcome. A smile spreads across he face, and she opens her arms out toward me, offering a warm hug.
"C'mere," she says softly.
I move closer to her, lying down next to her in her giant twin size bed. We wrap our arms around each other, and I close my eyes, trying to enjoy the feeling of having her so close to me. I snuggle deeper into her embrace, my tail swishing happily against the bed sheets. Her fingers trail through the fur behind my ear, caressing the soft tuft with gentle familiarity. Cuddling soothes me in a way nothing else can.
"Mmmm..." I mumble sleepily. "This is nice."
Mia looks really cute even without all the makeup on. She's wearing a black T-shirt and a pair of grey sweatpants which fit snugly around her hips, showing off the curves of her figure. Her long brown hair cascades down her shoulders and falls past her breasts, which are pushed up and slightly forward by the tight shirt. Her fur is silky smooth, not a single strand out of place. I wonder how much time she spends in front of the mirror trying to look perfect, even though I'll always find her prettier than ever. I bury my face in her chest, the soft fabric of her shirt tickling my snout. Her breasts squish softly against my head, and I let out a contented sigh. Hehe, imagine if I just grabbed 'em right now. That'd be pretty funny... giving my sister's tits a squeeze. The thought sends a sudden rush of blood to my groin, and I wince in embarrassment as I feel myself growing hard. My cock presses uncomfortably against her thigh, and I'm pretty sure she can feel it too. Mia gives a quiet laugh, which only makes me blush even more.
"I... I really don't know how that happened..." I mumble into her cleavage. 
She gently runs her fingers through my fluffy chocolate locks, looking down at me with amusement. She doesn't respond immediately, making a million scenarios flash through my mind; none of them ending in any good ways. It's only been like fifteen seconds, but it feels like hours have gone by already.
“Hey,” she speaks up, breaking the silence between us.
"Hmmm?" I hum, looking up at her.
“Wanna see something cool?” she asks, taking my chin in her hand and pulling my face closer to her own.
“What is it?” I ask curiously.
“Close your eyes and keep them closed tight. Don’t open them till I tell you to.” she replies, before pulling away.
I close my eyes obediently and hold perfectly still, listening intently as the sound of shuffling blankets and fabric follows. After about five seconds pass, she speaks up. 
"Okay... open them!"
I do what she tells me to, and I nearly faint at the sight. There she sits, not a single article of clothing in sight, a smirk on her lips. She twirls her hair idly while I stare wide eyed at her, my mouth agape. Her slender frame glows with the soft sunlight streaming in through the window, her legs crossed casually, one knee bent and resting on top of the other.  Her eyes sparkle with mischief, and her smile only grows wider.
"Holy shit," I breathe out, closing my eyes briefly as I try desperately to come to terms with what is happening. “I’ll be honest, this is the last thing I expected to see…”
“This is exactly what you wanted to see, weirdo,” she replies slyly. “I know you want to screw me. Stop acting like an innocent little puppy.”
“Okay, fine…” I concede defeat. “You could have just gone along with it.”
“Nah.” she smirks, shaking her head. “You’re really bad at hiding it. Now whip that dick out for me, nerd.”
I blush under my sister’s gaze, embarrassed that she was able to read me so easily. I quickly yank my pajama pants down, revealing all six inches of my throbbing length. My cock stands proud, its shaft straining to reach her, desperate to feel her touch. Mia giggles when she sees my erection, biting her lip seductively. God, she has no idea how hot I find her right now.
“Pretty big.” she remarks, running her thumb gently over my tip. “But I’ve seen bigger.”
“Oh, yeah? Where?” I reply, looking away from her in annoyance.
“None of your business.”
“Hmph…” mutter, crossing my arms.
“What?!” she laughs. “I didn’t say it was small!”
“Whatever,” I scoff, rolling my eyes. “Are we gonna fuck or what?”
“Ugh, you’re so fucking impatient…” she sighs exasperatedly. “Come here.”
Mia leans in closer to me, snatching my glasses and placing them neatly onto the nightstand. I lie down on my back submissively, spreading my thighs apart for her. She gets on top of me, hovering over me before leaning down and pressing her lips firmly against mine. I wrap my arms around her waist, kissing her back eagerly. Her tongue darts out to brush against my lips teasingly before darting inside my mouth to playfully dance around with mine. I whimper softly into her mouth, moving my hand to grip her ass lightly as she straddles my hips. I grind my hips up instinctively, wanting to press my cock up against her pussy. After a moment of pure bliss, we both break away breathless, her forehead pressed lightly against mine. Mia brushes a stray piece of hair away from my face, tracing her finger down my jawline as she stares down at me, completely unashamed of her blatant display of affection.
“Ready to stick that big dick in my ass, stud?” she whispers, causing goosebumps to appear upon my body.
“Oh, in your butt.” I murmur in response. “But isn’t that… dirty?”
“Do you not wash your ass when showering?” she retorts.
“Good point.” I concede.
Mia slowly lowers her asshole down onto my cock, and I gasp loudly in surprise. Her tight hole grips my shaft  causing me to twitch beneath her. She leans down to bite my neck, sucking and nipping at my skin as she continues to move he back and forth over my dick. I let out a loud unrestrained moan, quickly regretting that decision when she puts her hand over my mouth.
“Shut up!” she hisses quietly. “They’re gonna wake up!”
Oh, right. Our parents live in this house too. I tend to forget details like these when I’m boning my sister.
I nod, silently apologizing. We continue our fuck session, Mia’s tight ass gripping every inch of my cock. The old bed springs creak underneath us, and my breathing quickens. I push myself further forward as deep as I dare, her anus clenching painfully around my cock as she continues to ride me steadily, never slowing down her pace. I grit my teeth, my dick shooting a huge load straight into her bowels. She whines quietly, throwing her head back in pleasure. My softening dick slips out of her ass, my balls completely drained. I collapse onto her pillow, breathing heavily as I stare at the ceiling, wondering what I did to deserve such amazing sex. Mia crawls over to hug my side, stroking my hair as I lay there dazed.
“We should have done this years ago…” I pant, my eyes fluttering shut. “Can we start doing this everyday?”
“I dunno about everyday, but… I’m right across the hallway, you know. If you ever feel like sticking your dick in something, just go and knock on my door and I’ll take care of you.” she chuckles.
“Best sister ever…” I groan dreamily, feeling warm and fuzzy all over.