Dawn is, she reminds herself, Tau-Estes’s favorite student. She was what some had called a once-in-a-generation talent. She had an innate connection to the mesmer arts that left most of her peers flummoxed. With barely taking even the slightest precautions she can do what often breaks the minds of lesser mesmers. Dawn knows that she is gifted.

It isn’t hard to be sure of that when my sister is prancing in front of me like a dog on a walk.

Dawn holds onto this thought – this belief – with as much conviction as she can muster. Mesmerism needs the practitioner to be sure of their own ability for it to not glitch, for the coverage provided by it to not momentarily and then totally lapse. Having some sort of illusory misfire while palming her sister’s ass and holding onto her leash while they walked down the street was not an especially appealing idea. So Dawn tries her best to feel like she’s the hottest shit to ever step foot on this sidewalk.

Katie walks in front of Dawn, hips sashaying with an exaggerated flair that Dawn is sure she’s responsible for. The leash, a deep lavender colored thing, trailing from the D-Ring of Katie’s collar to be slung over her shoulder and back into her sister’s left hand. Dawn keeps a firm grip on it, more to steady herself than it is to keep Katie in check. Katie will keep herself close because to do otherwise would make her a bad girl and the thought of doing that is almost radioactive to Katie. Dawn should know; she’s the one who planted that idea in her head.

Katie walks as if this were just how going on walks worked, dutifully walking towards Hyde Park with nary a concern that they are being publicly indecent. The pair passes in front of Rivers and Crows, Dawn’s favorite bookstore that sells genuine occult texts and not just pop witchcraft. The younger of the sisters sneaks a peak inside, towards the bookkeeper who always calls out her name when he sees her walk by. He always manages to convince her to buy something, too.

Good, she thinks when the elderly man with his gray and brown beard doesn’t so much as blink when pass the open oaken doorway. He can’t see us. It’s going to be fine. Everything is fine, actually.

Katie taking the lead was a necessary step. It takes an immeasurable amount of pressure off of the younger sister. Dawn has far more important things to worry over than something as pedestrian as minding where she was walking.

For one, the most prominent problem is the fact and magnitude of Katie’s ass. It’s at the forefront of every thought that Dawn can muster. It’s so big and she can’t quite get her hands off of it. I’m going to fuck her soon, is repeated over and over again between other thoughts that it may as well be a mantra born out of years of meditative practice. Between her bouts of reverent adoration for what would certainly soon be sullied, she directs as much attention as she needs to the wider world. There’s a bigger problem than simply fondling her oblivious sibling, surprising absolutely nobody but Dawn herself. Doing an enchantment to make everything seem actually normal to people would be a lot more difficult to achieve. Dawn knows this.

It’s the safer choice to try and adjudicate what someone views as reasonable, but it requires on the fly adjustments to what an arbitrary person sees as coherent within the boundaries of their culture’s broader network of acceptable inhibitions. It isn’t necessary or even advisable to adjust someone’s actual and personal inhibitions, her instructors have always told her in contexts that did not ever involve making your sister take your shaft while the people around you treated it as ordinary, but the principle still applies. That sort of mesmerism is a much more difficult and prone to failure process. It is safer in that it leaves very little room for error and it doesn’t require maintenance on the entire perception collective. Done right, it only requires one adjustment for each new observer.

Dawn could do that. That’s not what she finds concerning. What Dawn is pretty sure she cannot do is keep up the sustained mental effort necessary for the feat when her cock is buried as deep as is possible within the confines of her sibling’s butt. Dawn sees sparks when she masturbates and she is a virgin when it comes to anything but her sex toys and her hands. Before her escapades with Katie, Dawn hadn’t so much as made a plan to do something as stupid as this.

So, she’s doing the much simpler task of obfuscating observational capacity. Nobody notices they’re there. It’s simple; it’s such a basic trick because the human mind already doesn’t want to see much more than what it absolutely needs to. In fact, mesmer studies claim that it yearns to cull unnecessary visual data and so it’s no problem to shove a specific, arbitrary thing into that deletion buffer. The data is gone before the conscious mind ever has the opportunity to get the information because it’s routed away from it. It doesn’t quite hold against any others with the same gifts, but they’re a rare enough breed as it is. Dawn is fine. Why would any other mesmers be at the park? That’d be ridiculous to plan for.

The sudden bark of the Katie’s voice asking, “Hey, are you listening to me?” and the heaven-sent cushions of Katie’s tush being pressed back into her pawing, kneading hand is enough to jostle Dawn out of her thoughts. Her gaze had apparently fallen to stare down at the cracked concrete below the two of them and was now fixed entirely on her sister’s back and the perfect swell of her rear. They are stopped. Dawn’s cheeks are red, too, aren’t they? Fuck.

“Uh- Uhm. Sorry, I was, uh,” she pauses. What was Katie even trying to say? Dawn’s eyes search her sister’s own for any hints and she comes up short. She instead says, “I was just thinking about something. What were you saying?”

Her sister’s lips turn to a playful grin that she had only ever used when she caught Dawn getting away with something. Dawn’s hand instinctively releases from Katie – she’s still not quite sure that the enchantment on Katie’s mind is going to hold for much longer. It shouldn’t have lasted this long in the first place; she hasn’t done anything to maintain it.

“You’re so focused on my butt. You’re acting like you’ve never squeezed it while were out before,” she says with a little laugh. Dawn’s breath quickens and she is forced to choke out an instinctive urge to push back on Katie’s capacity towards self-rationalization. It’s always best to let a subject lead their own deception, she’s pretty sure one of her instructors had once said to her. “Anyways, I was just asking where we were even going in the park? It seemed like you wanted to do something specific here, but you didn’t say what.”

Dawn stares dumbly at Katie for a moment longer before her gaze shifts to her surroundings. The pavement was mostly the same, but instead of brick and glass flanking one side while oversized SUVs sped on the other she was on a wide path with bushes hemming in the main pedestrian thoroughfare. A few people instinctively dodge the two of them while Dawn processes where she is. The small man-made lake off to her left, the trees, and…

That was faster than I expected, Dawn realizes. She squeezes her eyes shut for a moment. I’m so fucked. She inhales sharply through her nose and opens her eyes again. Okay. Focus.

At the center of the park was the fountain that she planned to ruin her sister over. The fountain was a large, tiered thing with a granite statue at its apex. It commemorated some war hero from decades past holding a rifle in one hand and a first aid kit in the other. She didn’t know exactly who he was, neither Dawn nor anyone in her friend group especially cared for local history, but she had had a brief thought when she had first moved to this city that he’d look better as a woman. Women in uniforms always got to her. Women in general do, I guess, she thinks to herself. Especially when they’re related to me, she continues to think before mentally kicking herself.

Said fountain dedicated to whomever the fuck was surrounded by a small sea of people. There were a collection of chess games, maybe five or so, off to the western side and what looked to be a yoga group meeting off on the other. The benches that encircled the space were mostly occupied. Between them stood the odd gaggle of bodies chatting and enjoying their days as if there weren’t two massive perverts within spitting distance of all of them.

Dawn had forgotten that today was a Saturday and that it was a nice day. She did not consider that there would be much of anyone here today. Dawn thought it was Tuesday. This is okay, she tells herself in a way that doesn’t necessarily feel like a lie when she thinks it. She is powerful. She can make it work. Dawn cannot forget that for even a moment or else she is going to falter and faltering here and now is maybe the worst thing that she could do.

Despite her cocksure certainty of her own power, or maybe due to her body’s effort to spite it, Dawn’s voice catches in her throat when she first tries to speak. Katie looks like she’s about to laugh at her and, Dawn is certain of this, her doing that would probably make Dawn fuck her in the bushes before she remembered to strengthen the mesmerism. Dawn swallows harshly and tries again before Katie has the chance. She does better this time, “Th-there. The fountain.” Dawn loosely points towards it with the hand still holding the leash like the lifeline that it certainly is. Dawn has it wrapped around her fist in three taut lines of purple material and black stitching.

Katie looks over at it and looks back with a grin that shows off teeth and Dawn once more deeply fears means that Katie has caught onto the game. Katie of course hasn’t and instead says, “Oh, alright. Thanks for taking me on this walk, by the way.” Katie mentions, grabbing onto the leash where it hangs over her shoulder and tugging it forward when Dawn’s legs refuse to move. “I’d been feeling very off lately. This is nice.” Though she’s looking ahead, from Dawn’s position behind and slightly to the left of her she can see the edge of Katie’s smile. The sight of it makes Dawn’s cock twitch. Wait, she tells herself. Be patient, holy shit.

Dawn’s own smile is fragmented as she eyes all of the people at the fountain and the encircling path around it. None of them seem particularly attentive even without the subtle magics toying with their perceptions. She’ll still want to shore up her technique when trying to keep the crowd’s gaze off of them. It’s not an impossible ask of her. Under normal circumstances it wouldn’t even be especially difficult, it’d closer to tying one’s shoes while they were sleepy than it is would be to doing coke and then immediately trying to get her deposit back. What she is planning to do is closer to the latter. No pressure.

The main problem is of course her mounting arousal, and her cock helpfully aches in her shorts to make that point clear. The thing is already oozing pre-cum onto the fabric and she is dreading doing her laundry. Dawn makes an earnest attempt to speak and manages: “Y-yeah. Uh. I’ll just need you to, uhm.. Bend over it. For me. With your butt sticking out? When we get there?” Dawn is forcing out her words like she’s biting each sentence, each word, as it passes through clenched teeth because she knows that she is in over her head. If she fucks up, if her concentration falls short for but a moment, she is metaphorically, spiritually, and not the least physically fucked. She might even get expelled from the institute. Or, worse, she might get a grade deducted for the sheer and unabashedly awful things she’s doing to her sister and her lack of tact in keeping a lid on it.

An expulsion she can deal with, but being a B student​? Fuck, she’d rather die.

A fleeting part of her psyche, a vestige that is rapidly withering away, warns her. This is the last time we can stop, and If you keep going we can’t take this back! This is mostly true. Dawn has already entirely betrayed her sister’s trust, but she hasn’t yet taken her pride and lost her own. She could, even now, choose to pump the brakes.

That miserable, pleading vine of thought and worry, Dawn’s last remaining shred of dignity and shame, dies when Katie presents herself.

Katie’s own shorts – shorter than Dawn’s and barely able to sincerely be called booty shorts – were doing approximately fuck and all to hide the elder sibling’s rear beforehand. Now? They are doing the opposite of hiding. They are framing it in space. The fabric is stretched absurdly, especially with what was the obviously still growing evidence of arousal that Dawn saw on her sibling. Both of their cocks are hard and, Dawn’s psyche helpfully provides here at the step before the apex of her depravity, Katie’s is bigger. The thought makes Dawn’s spine quake in anticipatory need.

The mass of people around them continue to not notice them. Dawn would know if they had; the sense of sudden panic or uncertainty or even arousal would be a big enough disturbance in the natural neural flow of the crowd to be detectable. Unless someone here knows how to hide, she thinks, but Dawn is pretty certain that she’ll be in and out before that is a concern.

Dawn clenches her fists. She smiles in a way that betrays how eager she is and blushes because she had intended to seem cool. She releases her grip just barely enough to grip onto the backs of those beautiful black and white frames that were all that stood between her and her own personal oblivion. There’s no going back. She’s doing this, apparently.

With skin contact established, Dawn hooks herself into Katie’s mind. The lack of resistance is one of Dawn’s new favorite things about her sister, and she had found so many new attributes of Katie over the past couple of weeks to compete with that.

Dawn leans forward until her chest is pressed against Katie’s back and her lips are adjacent her ear. Dawn takes a moment to drag herself to something near sounding coherent, bites down on her lip to get her mouth to comply long enough for her to speak, and says, “I’m going to fuck you.” It comes out remarkably clearly. The rest is less refined, “You’re- I’m-… I’m going to fuck you, right here, and you’re going to, you know, enjoy that. Okay?”

Katie, as good of a subject as she always is, nods in placid agreement. “I cannot wait for you to have sex with me.” Katie’s voice is monotone and slow and it makes Dawn’s breath hitch.

“G-good,” Dawn says. She looks, once more, to the people around her. She wills them into treating this section of the fountain promenade – this tiny, tiny sliver of reality, small enough that it should bother no one if she temporarily claims it as her own – as if it were nothing more interesting to look at than a streetlamp. There is nothing worth remembering or looking at here is about as simple of a command as she can press into the herd of the masses. It’s easy. Everything is fine. She’s going to make her sister take the full length of her (It’s not even that big, she can handle it, Dawn admits to herself while biting her bottom lip) and it’s all going to be okay. She just needs to scan the area once more, she just needs to make absolutely certain that-

Katie waggles her ass in the air when Dawn releases the hook on her mind and the anxious concern that seems to surround Dawn like a thick miasma vanishes into a puff of neurological smoke. Both pairs of shorts fall to the ground as quickly as the physics of Dawn’s hands and her and her sister’s clothing allows. Dawn is greeted by the sight of Katie’s freckled ass, she sees the nearly transparent specks of an angel’s kisses on pale mahogany cheeks and she sees her sister’s cock standing at attention in front of a far too cute, recently shaved sack.

Fuck, even her dick drools more than mine does, Dawn realizes. She’s not sure if she’s breathing anymore. She really doesn’t care.

Despite how flustered Dawn has been about this whole thing, she didn’t forget the important parts. Mostly. She didn’t bring a condom but unless Katie sports some particularly peculiar biology she, at least, cannot get pregnant. Katie will have to deal with a creampie. That’s fine. Dawn has been telling herself that the incest is fine because neither of them can get pregnant from it for two weeks at this point and she isn’t going to stop and doubt herself now.

Dawn crouches down to get at the pocket of her dropped clothing and pulls out a small bottle of lube that sports a cute green and blue label. The position she is in gives her a view of the underside of Katie that, if she weren’t in a rush, might make her stop and stare until the sight were permanently etched into her retinas. It is only the aching of her own shaft, perky and veiny and making a mess of her clothes fuck-fuck-fuck- that makes her get up, kick her underclothes away, and start working the lube.

A messy handful of it falls onto her hand and she first works it over herself. It’s cold and wet and holds the promise of Katie’s anus with it. Her breathing is erratic, she realizes, but doesn’t stop to do anything about as she works another handful around Katie’s rear entrance. Dawn realizes that she doesn’t know what to do with the bottle of lube, exactly, and eventually settles on setting it down on the stone of the fountain before that hand finds a better task in roughly handling her sister’s chest. Her fingers squeeze at one nipple and Katie lets out a moan that might as well be a nuclear strike for what it does to Dawn. She slips her middle finger, and then her ring finger, into Katie. Dawn leans in again and bites down on her. Muffled against the neck of the other woman as she is, Dawn still manages to say, “S-spread your – legs. Further. Please.”

With a shudder of pleasure Katie does and after another moment of finger-fucking (It’s just to spread the lube, Dawn lies to herself) Dawn’s digits retreat to make room for herself. She uses her fingers to scissor Katie’s cheeks enough apart to make entry easy. Dawn briefly pauses, for just a second, to make sure that she’s really doing this. She’s really going to have sex with her sister right here, right now?

Yeah. I am.

Dawn’s cock spears her sister’s sphincter without any giving herself further time to spiral into self-doubt. She presses it in deep, letting out a startled little squeal as it squeezes around her. The hand working on Katie’s chest squeezes a bit too tightly so that Dawn can stay stable and Katie makes a quiet noise of protest.

“Sorry, sorry,” Dawn apologizes. She finds her footing and adjusts her arm to wrap around Katie’s waist instead of using the much more sensitive breast as an anchor point. Dawn starts to rock her hips. The feeling inside of her sister is almost magical. It’s so warm and it seems to be almost perfectly sized for her cock. She thrusts slow and far, hilting herself in her sibling with each push and nearly fully exiting her with each pull.

Katie sounds serene, Dawn thinks. Both of them were are equally loud. Their moans were maybe even a bit too loud, though Dawn isn’t able to think of that on account of the bliss that she’s struggling through. Their sounds are breathy, squealing noises that coil up into balls in their chests and billow out like a songbird’s cries. Something low tugs at Dawn’s awareness, a sense of something in her periphery but she is too focused on the sensations. Katie’s own song is lighter than Dawn’s own cooler, more bass-y coos and whimpers. Beneath their voices, the ever increasing frequency of plap-plap-plaps coming the sacred space between their thighs forms a lurid undercurrent that seems to exist entirely to push Dawn forward. She flushes and the sound at the same time as she is driven by it.

Dawn’s torso is entirely wrapped around her sister at this point. She bites, she nips, and she leaves at least a dozen marks that will certainly stick and a half dozen more maybes that she seriously hopes will last. Katie tries to say something that gets strangled in her chest but sounds maybe like “harder” and Dawn can do nothing but oblige. She clings tighter still with both arms pressing Katie’s body against her own, seeking to reduce the distance between them to the atomic scale, while she ruts her sister.

In the corner of her eye, Dawn can see a couple toss a coin int the fountain and make a wish. Dawn watches them with wide eyes and she finds that their simple proximity makes her whole body clench in anticipation for getting caught. It’s all that she can do to try and keep the obfuscation going while also ensuring that Katie doesn’t hurt herself against the brickwork of the fountain.

Dawn’s capacity to hold out doesn’t last. She doesn’t even realize how close she is, really, until it’s too late to do anything about it. She keeps fucking and suddenly she lets out a whimpering squeal of a cry. She digs her digits into her sister’s sides and finishes inside of Katie. She jams her sibling back and against her groin and whimpers out a series of plaintive coos and groans that Dawn can hear echo off of the trees. She doesn’t produce much with her orgasm – her dick contributes a few spurts of cum into her sister at best before Dawn gives one final bite to Katie’s neck that pushes Katie over her own edge – but the satisfaction of filling up her sister is an all-encompassing thing. A shroud of joyous ecstasy flows over her while Dawn pants and Katie mewls. The two of them are stuck together for a beautiful and terrifying moment, each of them putting in half of the work that it takes to keep the whole structure of their coitus from collapsing to the ground below. Katie’s knees are shaking and it’s all that Dawn can do to not hump her once or twice more to see if she tumbles.

Dawn closes her eyes and takes in a deep breath and what fills her nostrils is chlorine and perfume and freshly cut grass and cum and she cannot be more exhilarated than she is right now. She tries to find the words to speak but they seem to die on her tongue or in her throat or anywhere but at the edges of her lips.

Katie, of course, speaks first. Even freshly railed she is more put together than Dawn. “God, Dawn,” she blubbers, pressing her rear back again, against the softening-but-still-penetrating dick. “You’re so good at that. If I’d have known this is what we were doing, I’d have…” She shakes her head as she loses her train of thought. Her sibling’s fluids slowly drool out of her freshly used hole and roll down her thighs while Katie’s own semen shines brightly off of the stones below. She shudders.

Dawn opens her eyes. She has a witty response, something about cats and lost tongues, and then her heart stops in her chest. Her mesmerism was still active, of course. Even in the throws of orgasm the average person could barely hope to see a properly skilled practitioner such as herself. But she had missed something in the chaos of their union. There was a presence, somewhere, that she failed to account for.

With her panties down and her dick still stuck into her sister, she weakly raises a hand and offers half of a wave to a blue-haired, older woman just twenty or thirty paces away from them. The woman’s gaze is fixed upon them in an unblinking stare. How long had she been watching? There’s no way for Dawn to know. How, precisely, Dawn had missed the clicking of those heels or the sparkling of the otherwise azure dress, is also a mystery to her. “He-y, uhm.. This isn’t what it-”

Katie, still entranced as she is in ways that frighten Dawn as much as they make her cock twitch even now, beams at the woman. “Oh! Miss Tao; did you need my sister for something? She and I just finished; I – ghh – wouldn’t suggest sitting right here,” she says and then pants for breath. She straightens her posture a bit and Dawn’s dick schlicks out of her. “It’s pretty messy right now.”

I’m in so much fucking trouble, Dawn thinks.

She is. Though, from how Tao-Estes looks like she is going to combust, from how her hands shiver and from the faint parting of her lips, it may not be in the way that Dawn thinks.

✶✶✶ FIN ✶✶✶