Some high Risk backseat fun while your Parents drive you to the Camp site

Lyra teases you mercilessly the days between getting back from your parent and the lead-up to the camping vacation, constantly teasing with hints of a fun little game she can't wait to play and how in the middle of nowhere there wouldn't be any pesky morning after pills to stop her swimmers. She drops hints about having all the taboo fun you can imagine right under your Mom and Momma's noses and seeing how far you can both go without getting caught. You're not sure how much Lyra is even joking either, all you know is that through the anxiety of how much of a risk both ideas were, there's a definite excitement to it.

On the day of trip you get ready to start loading your bags into Lyra's car when she tells you not to bother as she pulls out her phone and starts a call. "Hey Mom, Is there any chance you can pick us up, my car is acting up and I don't want to risk it breaking down at the campsite," Lyra asks with a smile.

"Sure Honey, It might be a little cramped with all the gear, but I'm sure with a little squeezing we'll you and your bags in," Your Mother replies cheerfully. "Will one of you be ok to sit on the other's lap?" Your Mother adds thoughtfully. "If not we can always reschedule, the company that runs the campsite are really laid back and flexible," Your Mother continues in a soft helpful tone.

"We'll be fine," Lyra replies.

"Well, in that case, we'll swing by and pick you up in 15 minutes," Your Mother replies sounding happy.

"Awesome, now it's really going to feel like old times," Lyra replies with a giggle. "Although I think since I'm bigger it might be Misty riding in my lap this time," Lyra adds with a soft laugh.

"I'm sure you can take turns if it gets too uncomfortable," Your Mother suggests.

"We'll figure something out, don't you worry," Lyra replies looking back and giving you a wolf-like smile. "Alright we'll see you shortly, Love you Mom, Bye," Lyra concludes hanging up the call and turning her full attention to you and the outfit you're wearing. A thin sleeveless top and a short tennis skirt to show off your long legs. "Are you wearing panties under that skirt?" Lyra asks in a sultry tone.

"Yeah," You reply with a mixture of nervousness and excitement from the hungry look in your Sister's eyes.

"Take them off and hand give them to me," Lyra says in a calm yet commanding manner.

"Seriously?" You ask, hoping this was another of Lyra's jokes

"Yeah, you'll get them back at the campsite," Lyra replies with a grin holding out her hand expectantly.

"Fine," You reply with a half laugh of disbelief as you slide your panties off and drop them into your Sister's outstretched hand. "Do I want to know what you're planning?" You ask a mix of nervousness and excitement flushing through you.

"Oh, you'll know soon enough," Lyra replies with a giggle as she holds your panties up to her face and takes a deep breath. "Now if you'll excuse me, I need to double-check we've packed everything we'll need for fun," Lyra continues with a sultry giggle as she slinks away, taking another deep breath of your panties.

You're more than a little nervous about why your younger Sister needs your panties, or more likely needs you not to be wearing them, especially with such a long trip ahead in close proximity to your parents. This nervousness only increases when your parents' car arrives and you squeeze your bags into the back leaving just the seat behind the drive for both you and Lyra to share like you've done a few times on previous vacations when your Mom had a much smaller car.

"Alright I'll get in first, you sit on my lap, Mist," Lyra says as she hops into the car.

"Sounds good," You reply, feeling anything but good about this, knowing that your short skirt would offer little in the way of protection from your Sisters big hard cock.

"Just a few hours drive, we'll be there before you know it," Momma Genevieve says with a big smile.

"Although do shout up if you need to stop and stretch your legs," Your Mother adds helpfully.

"We'll be fine," Lyra replies with a giggle as she helps you slide onto her lap. "I've been told I'm very comfortable to sit on," Lyra adds in a teasing tone as her hands shamelessly grope your ass and thighs.

"Funny enough, your Mom tells me the same thing, or at least my face is comfortable for sitting," Momma Genevieve replies with a wonderfully dirty laugh.

"Genie!!!" Your Mother chastises, her soft pale features flushing red with embarrassment.

"Woah way to go, Momma," Lyra replies with a giggle which you join in with.

"Oh lighten up Judy, the girls know we have sex," Momma Genevieve teases, "Hell they'll probably hear us going at it if we don't space the tents far enough," She adds with another dirty laugh.

"Ok, I'm just going to set off and pretend I can't hear anything," Your Mom replies, her face looking almost sun burnt with how red it is.

"Sorry Judy, It just feels so nice not having to hide anything anymore," Momma Genevieve says with a big smile.

"I know dear," Your Mother replies with a soft sigh, "It's just I don't quite have that comfort discussing private things like that, especially in front of our daughters," Your Mother adds as she sets off.

"Ok, ok, I'll dial back the teasing a little, but I think there's nothing wrong with a little openness," Momma Genevieve says with a broad smile.

"I agree, I think family is for sharing," Lyra replies. "And I have so much I want to share," She whispers into your ear her cock poking your soft ass from below. "Don't you agree, Sis?" Lyra continues in her normal volume.

"Oh yeah," You reply with a nervous laugh as you start to realise what your not-so-sweet or innocent Sister has in store for you.

To her credit Lyra does at least wait a good half an hour before she starts to tease you, her hands sensually caressing your legs and ass to begin with, before growing bolder and teasing your upper body, cupping and squeezing your tits. The soft drone of the car moving and the music drowning out your soft moans of pleasure as your pussy grows wet and starts to make a wet spot on the shorts Lyra's wearing. All the while Lyra slowly adjusts the piles of luggage and camping equipment until there's more than enough to hide what she's doing to you in the back seat.

"Can I crack the window open a little, it's a little hot back here and I don't think the AC is working that well with all the stuff in the back," Lyra asks loudly while her hands slide up the insides of your thighs, making you squirm in delight as her soft hands bring a spark of excitement the nearer they creep towards your exposed sex.

"Sure thing, Sweetie," Your Mother replies.

Lyra lowers the window a crack, not wanting to give anybody driving alongside you too much of a peek, but giving a crucial source of fresh air to cover the growing scent of your arousal. Not to mention an extra layer of sound to cover up the sounds she plans to be making, including the small squeak of surprise when Lyra lifts you off her lap for a moment, so she can slide her shorts down just enough to free her thick swollen cock. You let out another yelp of surprise when you feel your slick wet lips brush against Lyra's cock, a wave of excitement and panic hitting you hard as you begin to wonder just how far Lyra plans to take this.

"Everything alright back there?" Momma Genevieve asks, her eyes looking back at you both through the rearview.

"Yeah, just didn't give Mist enough of a warning when I moved," Lyra replies with a soft laugh.

"Do you want me to stop?" Your Mom replies

"No Mom, we're good, aren't we Mist?" Lyra replies with a smile as she wiggles her hips slightly, causing her cock to grind against your sweet folds.

"Yeah Mom, we're great," You reply with a smile, feeling an intoxicating rush from doing something so taboo, so close to your parents.

For the next 20 minutes, Lyra teases you against her cock, gently sliding your back and forth in her lap, driving you wild, but just depriving you of enough sensation for you to cum. Eventually, you find yourself trying to buck your hips to give your Sister's cock just enough of an angle to brush against your aching clit, but Lyra's strong grip on you prevents you from achieving this.

"What's the matter, Sis, just teasing isn't enough?" Lyra whispers into your ear.

"Please, I need to cum," You whisper back in a needy tone.

"Now that you mention it, you are seemingly much hornier than usual," Lyra whispers back with a soft giggle. "Is it because our Moms' are so close?" Lyra asks in a soft sultry whisper. "Or maybe, you're extra horny because of something else?" She adds in another breathy whisper.

"I don't know," You plead in a hushed tone, trying your best to wiggle your hips to get more stimulation.

"Well there is one thing I could do," Lyra offers with a hushed flirty giggle as she lifts your hips while sliding you forward, causing your Sister's cock to lift upwards, the tip slipping between the soft slick outer folds. "Although I don't have a condom and I can't exactly pull out like this," Lyra whispers suggestively. "And If I'm right about the other reason you could be extra horny, then it could be very risky," Lyra continues with a soft whisper. "It's your choice if you want to escalate this into a game," Lyra states in a sensual tone.

You know exactly what your Sister is hinting at, sadly the math checks out assuming your cycle is more reliable than it had been back in Vegas. There's every chance you were in or near the most fertile part of your cycle with your Sister's cock so temptingly close and your body so **** to feel her inside of you again. You were already playing with fire as is, not using condoms since Vegas, relying on Lyra to pull out or for you to dismount in time, there were already some close calls since you were lax back when you thought you might already be pregnant. After all that sweet sensation of your Sister's thick potent cum flooding your defenceless pussy is a veritable sirens call of pleasure.

You know it's the wrong move, you know it's dangerous, especially given the bullet you dodged just a few weeks ago at your parents. Yet despite this, you feel your body moving, your hips sliding back as the tip of your Sister's cock parts the soft folds of your inner sex and slips inside your juicy pussy. You have to cover your mouth to suppress the groan of ecstasy, the feeling of Lyra bottoming out inside of your finally tipping you over the edge as you cum hard on your Sister's cock. The soft silky walls of your sex squeeze and caress the swollen length, eagerly sucking up every drop of precum from your Sister's shaft.

"Naughty Sis," Lyra whispers into your ear, biting down on her bottom lip as she waits out your orgasm. "No going back now, the only way you get out of this without my cum flooding your womb is to ride that razor's edge," Lyra explains with a husky tone. "Making me enjoy the ride enough to leave you in charge, without going too far and making me cum," She continues. "but stop for too long and I'll take over and I'll make sure I'm as deep as I can be when I blow my load inside that sweet unprotected pussy," Lyra coos.

At first, you barely register Lyra's words, simply enjoying the feeling of having her cock inside you too much as you begin to roll yourself back and forth in her lap. The sheer delight of this taboo act, so close to your oblivious parents only adds to the already wonderful sensation of your younger Sister's shaft sliding in and out of your slick channel.

"Oh and to make this game more interesting," Lyra whispers into your ear. "If you lose and I cum in you, then I'm not pulling out for the duration of this vacation," Lyra explains with a sexy little giggle as she reaches around and places a hand over your flat stomach. "So lose here and I'm going to ensure you get the Souvenier of a lifetime to remember this trip by," She explains with a grunt of pleasure.

You feel a dizzying mix of excitement and fear about the stakes of this game your Sister has you playing, your body and womb are on the line. You have to edge your younger Sister with your pussy, without going too far or stopping for too long, while also not drawing the attention of your parents and being caught in the act. You whimper as you begin to slowly lift yourself off your Sister's big fat futa fuckstick, before lowering yourself back down on it, the thick crown of Lyra's cock pressing against your cervix.

Starting with a slow deep pace feels like a good idea, with each slow steady drop you hear Lyra let out low groans and grunts of pleasure as your slick walls caress every inch of your Sister's cock. The noise and movements were minimal so there's little risk of being discovered by your Mom or Momma, even if they look back you could pass it off as just rearranging yourself for comfort. However, you start to notice the one flaw of this plan, when only a few minutes in, the sensation of feeling Lyra's majestic member and every bump and vein to it brushing against every weak spot of your silky sex is driving you wild.

Your orgasm quickly sneaks up on you, giving you just enough time to cover your mouth as you begin to cum hard on Lyra's cock, your juices leaking around her swollen shaft. You shake and quiver, leaning back against your Sister while the walls of your molten sex spasm rhythmically around Lyra's fantastic futa appendage, your body trying its best to betray your intentions and milk Lyra for her potent payload.

"Careful, Sis, keep milking me like this and we're going to need to start thinking of baby names," Lyra whispers seductively into your ear, her cock giving a heavy twitch for emphasis.

Once you come down from your sudden orgasm, you know you need to think of a better plan than just going slow, since in your current state you'll enjoy it too much and get your Sister off almost as fast as if you just ride her hard and fast. So you begin to experiment with alternating your pace and introducing teasing pauses to your movements, to give you a chance to eke out the time before you can't help but cum again. You hope that if you introduce enough variety and add in some other forms of teasing your Sister might not notice the pauses.

The plan works for a good 20 minutes, Lyra sitting back and enjoying you bouncing and grinding in her lap, leaning back and moaning softly into her ear while whispering various compliments about how good she feels inside you. However, your plan proves too effective and soon Lyra who's very much playing to win decides to start tensing her core muscles while you're fully impaled on her cock during the pauses. The tensing and relaxing causes Lyra's sizable shaft to twitch and stir your deepest depths which feels incredible, Lyra also rests a single finger on your aching clit, allowing the subtle vibrations of the car's movement along the road to transmit through and further drive you wild.

Once more you find yourself cumming hard on your Sister's cock and realising you need another new plan, especially since you have quite some time to go before you arrive at the camping site. "That's it Mist, keep cumming on my cock," Lyra whispers teasingly. "I can't wait to spend this trip breeding you," She coos while all you can do is writhe in pleasure. "But feel free to keep trying, it's only making the load I've got brewing for your fertile pussy, that much bigger," Lyra adds with a flirty giggle.

Not sure what else you can do, you decide to continue with your previous plan but shorten the amount of time you were pausing to give yourself a brief respite to recover. You start to feel out how long Lyra will let you rest by waiting to see how long before she starts to flex her cock inside of you or move her hand towards your clit. It does mean that you never quite seem to get enough time for that familiar heat and pressure of your next impending climax to subside, instead just lengthens the time before you cum, but it's the best you're able to manage. Edging both yourself and your Sister while hoping that you somehow manage to last.

"Alright, just another few miles to go," Your Mother announces, much to your relief.

"You both ok back there?" Momma Genevieve asks with a smile.

"Yeah we're ok, glad to be so close," Lyra replies with a grin, her cock twitching inside you for emphasis of her close she is.

"Well hang in there, we'll be able to stretch our legs in a short while," Momma Genevieve replies with a soft laugh.

The last few minutes you've been sensing just how close your Sister is, her cock starting to twitch more insistently inside of you, but no signs of it getting even harder like it does when she's very close to cumming, you, on the other hand, are right on the edge of cumming. So hearing that you were just a few miles out you decide to switch up your plan and hilt yourself on your Sister's twitching cock, riding out the orgasm and then trying your best to endure whatever she can throw at you the rest of the way there. If you deny Lyra enough movement then surely she'll get close but just short of what she needs to cum.

It's a plan which might work, a few miles would mean 5-10 minutes at most to resist your Sister's best attempts to make you cum and you'll get out of this without Lyra flooding your womb with her rich potent futa seed. There are just two small problems you weren't but would very soon become very aware of. Firstly a few miles is a lot longer when you're travelling on windy country roads. Lastly, you wouldn't need to provide the movement to help get your younger Sister off, the uneven and bumpy roads would do that for you.

You start to realise your mistake when shortly after enjoying the sensation of you cumming hard on her cock once more and then refusing to budge, holding yourself against Lyra, she doesn't try and shift you or resist, she just lets out a laugh by your ear. "Don't be too upset Mist, the odds were stacked against you," Lyra coos softly as she moves her hands only on your hips and holds you in place on her lap, just as the car hits the first of many bumps in the road.

"Sorry, country roads aren't quite as smooth," Your Mother calls back when she hears you squeak from the jolt of the bump causing you to bounce on Lyra's twitching cock.

"It's OK, Mom, I'm holding Mist nice and tight," Lyra replies with a giggle.

"Such a good Sister," Momma Genevieve replies with a laugh.

"If only they knew," Lyra coos into your ear, letting out soft groans as each bump in the road causes you to bounce up and down on her shaft, bringing her closer and closer to filling you with nothing you can do to prevent it.

All you can do is sit back, gently bouncing in Lyra's lap, feeling her heavy balls writhe and churn beneath your soft ass as well as the swollen tip of your Sister's cock pressing into your cervix, with each bump the car goes over. You close your eyes focusing on what you can feel, giving in to the pleasure of the situation knowing you no longer have any meaningful control. Your mind racing with excitement about what will happen next and how amazing you'll feel when Lyra erupts deep inside of you. A pleasure you've not felt but have definitely craved since Vegas.

You let out soft moans of pleasure which thankfully your Mom and Momma don't seem to hear over the sound of the music playing in the car. You feel Lyra's cock start to swell and grow even harder as she nears her peak, her balls a flurry of activity as they shift and writhe beneath you preparing their potent cargo for its own journey.

"Fuck I'm so close," Lyra pants in your ear, her cock twitching heavily inside of you and giving a warning throb. "About to make your Mommy, Mist," She purrs into your ear.

"Do it," You whimper back softly. "Knock your big Sister up," You add, feeling Lyra's cock give another heavy twitch as it pumps more precum against your cervix practically lubricating it in preparation for the cum.

"Oh fuck, I'm in love," Lyra moans softly as her cock begins throbbing inside of you. "Cumming!" Lyra growls in a low tone, her throbbing cock starting to pulse as her thick potent futa seed explodes out.

You feel the impact and warmth in your core as your younger Sister's cum hits the back of your womb, tens of millions of her sperm start spreading out, eager to find an egg to fertilise. The sensation of Lyra's cock pulsing and throbbing inside you, with the sweet heat of her potent cream filling you enough to milk another orgasm from you. Your slick sensitive walls tighten around your Sister's shaft and begin to work together, milking every last drop of virile futa seed into your defenceless womb.

You surrender yourself to the blissful feeling of Lyra breeding your fertile pussy, your Mom and Momma so close and seemingly unaware their daughter might be making their first grandchild right behind their backs. Lyra screws her eyes shut, silently praying this is the one that sticks, and hoping that between the phone stashed in the backseat pocket and the camera by her side were capturing enough footage to make a decent movie. Even if she doesn't end up submitting it to the taboo fan site, Lyra would love to rewatch this for her own personal enjoyment.

Completely oblivious to anything other than the sheer overwhelming amount of pleasure you're feeling, you find yourself excited to see just what else Lyra has planned for this vacation.