>The timestamp on the video file suggests it has been recorded only a few days ago.
>It's unedited, you can tell as much, if not from the few minutes of dead air at the beginning of the recording then from the short section where the camera settings are adjusted to produce a halfway decent picture even in the dark surroundings.
>A centrally-placed chair is the only thing visible, apart from the shelves filled with books and various odds and ends in the background. 
>Finally, by the time you’re about to close the video in boredom, your sister nervously shifts into the frame, keeping a wary eye on the reference screen of the camera while patting imaginary lint from her clothes.
>She’s wearing a plain black t-shirt and a short skirt going down to the mid of her thighs.
>After a few more seconds of straightening the folds, she sits down, taking a breath and slapping her cheeks before suddenly smiling at the camera.
>As if a switch had been flipped, the girl adopts a cutesy pose, flashing a wide, toothy grin and giving her invisible audience a double peace sign.
>"What’s up, everyone?" she addresses the screen with a voice much higher, much more girly and feminine than you know it. "It’s ya girl X-X-X-Sunnybun!"
>The audio quality is pretty bad, what with being scratchy and static-infested like you would expect from an on-camera microphone.
>It also doesn’t help that your sister is half whispering.
>"Hello and welcome to another of my Patreon-exclusive videos," she continues, giving the camera a smarmy little wink. "If you’re not of legal age, you should probably close the player right about now. Everyone else, please join me on another exciting adventure."
>Sunset adopts a more serious expression, making a gesture around the room.
>"As you can probably tell, it’s nighttime, and I’m in my home right now. Everyone else is soundly asleep," the girl giggles sheepishly, "which suits me just fine. Let’s go."
>Standing up, your sister walks towards the camera, and the screen abruptly cuts to black for a second before showing her in a different location.
>An uncomfortably familiar location, to be exact.
>Grinning so wide she has to work to stay quiet, Sunset pans the camera around your bedroom.
>"Regular viewers will already recognize the location."
>Her whispering has gotten even quieter, to the point where she has to talk into the microphone directly, giving the audio the same quality as if she was directly breathing into your ear.
>The virtual closeness sends waves down your spine, as does the sudden realization of what Sunset is filming.
>There, sprawled out on the bed, dead asleep and oblivious to the entire spiel happening next to him, the target of Sunset’s 'adventure' is snoring lightly.
>The pose you are in is rather unflattering, as it seems your shirt has ridden up somewhat, exposing your stomach and the pair of boxers that have traveled to just above crotch level.
>"Jesus," your sister whispers into the cheap microphone, "I’m about to cream my panties from the sight alone."
>She creeps closer to the bed, a slender hand appearing at the bottom of the screen to carefully pull down your shorts.
>Even in the sparsely-lit room—and although the video quality could be better, to be perfectly honest—you can see why your sister is giggling.
>"Energetic as ever, I see."
>Giving your erection a few experimental pumps, the shameless girl continues to narrate her act of lewdness.
>"Not an unfamiliar sight to my regular viewers, of course, and I can tell you it is as red-hot and ready for action as always."
>Your sister keeps playing with your dick, lightly squeezing and jerking, apparently much to your sleeping self’s approval, if your expressions and soft moans are anything to go by.
>Fucking bitch.
>"I apologize, dear viewers, but I’ll have to put you down now. I’m going to scream if I don’t start masturbating soon."
>Placing the camera on the bed and angling it so that both you and her are still in the frame, the girl is quick to follow up on her words, spreading her legs to stroke herself.
>While you could already see her t-shirt and skirt combo earlier, the fact that she didn’t bother to wear panties is new to you.
>As is the entire image of your sister’s pussy, of course.
>Even the gritty video quality doesn’t leave much room for guesswork, what with the painfully-excited girl all but pumping into herself with her fingers.
>"Ah," she moans quietly, her eyes fixed on your dick glistening with precum, "does it feel good, Anon? Are you dreaming perverted things about your sister?"
>You don’t miss the fact that Sunset tries to keep the same rhythm with both her hands.
>"Shit," she pants, pulling back the hand she’s caressing herself with while still vigorously stroking your shaft.
>Sheepishly grinning towards the camera once more, she holds up her fingers in a peace sign again, although this time they are coated in her juices.
>"Almost came," she giggles, licking them clean. "Wouldn’t want to cum all over my brother’s bedsheets, right? Okay, seems you’re getting closer, too."
>Without another word, your sister bends down, letting your dick glide into her mouth.
>The audiostream is quickly filled with wet slurps, mixed with the occasional quiet gag when Sunset is a little over eager while swallowing your cock.
>Much to the viewers’ delight, your sister has angled herself so that her backside is still within the frame, giving the camera a delicious angle on her soaking pussy and her fingers still working on it between her thighs.
>Seriously, as far amateur porn goes, this is pretty much top notch, you have to admit.
>A wet pop is followed by the girl whispering again.
>"He’s about to cum, dear viewers. And I have a special surprise for you tonight."
>She grins back at the screen, although the excitement, the sheer lust in her expression turns it into something much more feral.
>"I will have to be very careful here, but please join me on my very first brotherly stealth-creampie. And who would be a better candidate to fill my pussy to the brim than this lovely young stud right here?"
>Squatting over your erection, Sunset lowers herself inch by inch, guiding your cock with her hands until the tip is just touching her mounds.
>"Ffffuck…"
>Sliding down onto your shaft, you can see your sister’s eyes roll back, the girl using one hand to support herself while tightly pressing down on her mouth with the other to stifle her moans.
>They still make it through, being picked up by the scratchy microphone embarrassingly clear.
>For the next minute or so, you watch your sister cum all over your dick, softly bobbing up and down while riding out her orgasm.
>You reached your own climax as well at some point, if the thick white glob she reveals while pushing herself off is anything to judge by.
>"Ha…Ha…" your sister pants, "now wasn’t that exciting, dear viewers? Wasn’t it hot to watch what a slut of a sister I am?"
>Bending down, she bobs her head on your cock again for a bit before pulling back and finally making to get off the bed.
>"Can’t leave any evidence…" she whispers conspicuously after swallowing, and the video cuts to black again after a few more seconds.
>Jesus Christ.
>"I-it’s not what it looks like…"
>Weird, you can still her voice even though the playback ended. 
>It takes a few moments longer than you would like to admit for you to realize that the last sentence did not come from the video.
>Turning around, you find the culprit all but twitching in place behind your chair, nervously fidgeting with her hands.
>"I didn’t, you know… I never actually uploaded any videos. I just found it fun to roleplay as if I did. Please, I just–"
>Your sister stops her mumbled apology, blinking a few times before cracking what could be a shrewd smile.
>"Did you…"
"Did I what?"
>You follow what Sunset is pointing at, looking down at yourself to find your pants and boxers around your ankles, your dick in your hand and firmly standing at attention.
"Motherfucker…"
>"So, uhm, the… next installment was going to be called 'The Return of the Brotherly Stealth-Creampie.' Did you… I dunno… did you want to help with that, maybe?"