Back Seat Sister Slip

"Really?" Baker asked, as I flinched my cock, deciding to counter her evil flirting with some of my own, by pretending I only needed a slight adjustment.

"Sure, it's the biggest Halloween party out there, all the hottest girls in school will be there, and you can always watch that silly movie anywhere, anytime," she said, noticing my flinch, and responding by scootching her ass around on my cock.

"It only plays in theatres on Halloween every year," I pointed out, flinching my cock a couple more times, going along with this strange backseat game, any hesitation to play naughty games with 'my very own sister' having flown out the window back when she jerked me off.

"No, we already have plans," Eddie protested, but the other two guys were willing to dump any plans, no matter how cherished, for the chance to hang out with my sister for a while longer, plus with all the other cheerleaders.

"Trust me," Shayla said in a seductive voice that made my cock flinch again, while assumedly doing the same to the other two guys (and maybe Eddie too, but I doubted it). "You'll have a great time!" She looked back to me knowingly.

"Can't we just stick to our plan?" Eddie whined.

"You can always watch it on DVD, or Blu-Ray, or whatever you have it on," she said, this time clearly grinding on my cock... calling my bluff.

Deciding enough of this teasing, no way did I want to come in my outfit again, which at this rate I would, and very soon, I said, as I lifted her up and off of my throbbing cock, "Actually Sis, watching it at home isn't at all the same thing as sharing it with a rowdy crowd in a theatre," I pointed out.

"That's right! And besides, we have plans," Eddie repeated, getting totally rattled because nobody except maybe for me, appeared to care about his sacred plans.

"Oh Eddie," Shayla wheedled, leaning forward and placing a hand on his shoulder. "Won't you attend this hot party for little old me?"

"I-I-I don't... know... h-h-ow... wh-wh-what..." Eddie stammered, totally losing his chain of thought, likely because this might be the first time a girl that wasn't his mother had ever touched him.

"Please, sexy," Shayla said, ignoring my whispered admonition that she was going too far, but instead, she reached underneath herself in the darkness and squeezed my cock, while repeating to Eddie, "For me?"

I groaned.

"Okay," Eddie agreed, then turned his head away, his cheeks burning red.

Shayla turned back to me, her hand still gripping my cock, and asked innocently, "Sorry bro, was I accidentally squishing you?"

"A little," I responded innocently since we were playing to the crowd, but getting super worried I might come again, since even normally, I could come twice pretty quickly.

"Let me reposition myself, then," she said, leaning over the bottles and resting her hands on Baker's leg.

In a moment of spontaneity... of lust... of my throbbing cock... or a moment of insanity... I used this brief reprieve to unsnap my costume and pull it up enough to release my cock, and untangle her panties from it. I then positioned my cock so it was angled directly towards her pussy, which I couldn't see in the dark since we'd just entered the highway... leaving the lights of the city streets behind... and waited to see how she reacted.

As she sat back down on my lap, it was her turn to gasp, as my erect cock slid deep inside her.

Now sitting on my lap, all my eight inches inside her pussy, she twisted around and gazed at me in complete shock and confusion.

I just shrugged... not sure how else to respond.

She was so wet that my cock had slid smoothly and easily inside her.

Was she wet because of sitting in my lap?

Had she been stimulating herself all this time?

These and many other questions swirled inside my head, but at the centre of my attention was her remaining frozen, with my cock deep inside her.

This was surreal!

It was so cool she hadn't freaked out! She hadn't moved away. She seemed to be pondering what to do next.

I didn't mean to, but my cock twitched inside her... making her moan.

"Are you okay?" Baker asked, concerned for my hot sister.

"Yeah, yeah, it's just a little leg cramp," she dissembled, as she was still looking back at me, then she moved her ass up and off of me... squirming around a little to get comfortable, which meant rubbing herself some more against my cock, which was now resting between her pussy lips, but no longer inside her hot hole.

I tried to appear impartial while she seemed to be processing what had just happened and what to do next... but she only asked, in a tone that indicated the other decision had now been made, "So you guys are all coming to the party with me, yes?"

"Do we have a choice?" Baker asked.

"Of course you do! You can either do as I say... or you can do what I say," my sister shrugged as she moved back a bit, and my cock head slipped back inside her.

Was that on purpose?

Or by accident?

The uncertainty was turning me into a horny mess.

I was desperate to fuck her... yet I wanted her to be the one to initiate it... although I already had initiated it when I positioned my cock at her pussy just as she was sitting back down.

I was stressed that I was committing incest... no matter that it was an accident on her part after a stupid, rash decision on my part.

I was worried about getting caught by my buds with my dick inside my own sister... which would be pretty damn hard to explain.

"Then my choice is to do whatever you say at all times," Baker said, drooling over my sister, my cock only about two inches inside her. Which was way better than zero inches!

"Oh, how sweet you are," she purred in full flirtation mode, letting out a soft moan as she once again leaned forward, sticking her tits in his face... my cock now just barely inside her.

A mixture of spontaneity... hormones... curiosity... mischief... lust... I made the decision for both of us, and I raised my hips and slid my cock all the way back into her pussy.

My sister froze again... again with my entire cock inside her... and she looked back at me with an expression that might mean anything... shock... curiosity... confusion... intrigue... is there a name for a facial expression that encompasses all those feelings into one? There should be, since I was looking at it!

I imagine it was similar to the look I'd had when she first grabbed my cock in our living room... God, that seemed so long ago now... when in reality it was only twenty-ish minutes ago.

Suddenly feeling guilty for what I was doing... I slipped out, and lowered myself back to my seated position.

Time stood still... although it was likely only a few seconds... before she turned away from me.

Feeling guilty and disappointed, I went to tug my costume back down over my hard cock, but Shayla reached her left hand, the one Baker couldn't see, back to my tool, positioned it against her wet pussy again and slowly... deliberately this time... lowered herself slowly back onto my cock.

My eyes went wide. She was once again sitting snugly in my lap... only this time there was a subtle but huge difference... she'd freely chosen to put my cock inside her!

"Oooooh," she moaned as she leaned back against me, growing accustomed to the eight inches of her brother's cock in her pussy.

"You okay?" Baker asked again.

"Yeah, my brother just has a lumpy lap," she explained, not moving, just resting against me... clearly unsure of what to do from here.

As was I.

Now we were both in limbo.

I was inside my sister.

My sister was sitting in my lap with her brother's cock deep inside her.

In the back seat of my friend's car.

With Baker sitting right next to us, the box of beer the only thing hiding my cock and where it was from his view.

"So... are you still dating Mike?" Baker asked, fishing for a miracle... oblivious to the one I was experiencing right next to him.

"Yes," Shayla said, studiously stoic, clearly processing her rash decision just like I had mine, but meanwhile continuing to flirt and tease poor old hopeless Baker, "But if I wasn't, I'd be all over you."

"Really?" Baker said, falling hook, line and sinker.

"She's kidding, actually," Steve threw into the mix. "Obviously, she'd be dating me."

"Maybe we should all just have a gang bang together," Shayla offered, which unintentionally made my cock twitch in her pussy... which made her in turn moan ever so softly... the idea of all four of us gang banging my sister was wild! Yet now that I was already inside her... I wanted her just to be mine and mine alone.

"Oh God," Baker gasped, as Shayla leaned across and brought her hand to his crotch to give it a playful rub... my own cock remaining halfway inside her.

"Shit," Steve gasped from the driver's seat, swerving a little.

Only shy Eddie remained still and silent.

"Or maybe just a bukkake," Shayla tossed out wickedly, the visual of my sister taking three loads of cum (excluding shy Eddie's) all over her pretty face also pretty fucking hot... since any bukkake was such a hot sex act.

This was my chance to pull out... to right a wrong... that is, if she considered this wrong... yet I stayed the course by remaining motionless... I'd let her decide what happened next.

This current episode had begun with her accidentally sitting squarely onto my cock. Then a bit later, I'd made the decision to purposely slide into her pussy. And then after I'd relented, she'd decided to sit on my cock again! And now here we were. This chain of events had been the most intense form of mutual teasing ever!

There had been no fucking. Only insertion. So far.

"Is this fresh growth because of me?" Shayla asked, after she placed her hand onto Baker's cock through his costume.

"Oh God," he moaned.

"I'll take that as a yes," she said, while openly rubbing his cock... my cock still resting halfway inside her.

"If you don't stop, I'm going to...." Baker groaned, and obviously came in his outfit.

As Shayla sat back onto my cock, tacitly declining this opportunity to terminate our incestuous stalemate, she said while she slowly moved her body back and forth, slowly fucking herself on my cock, "Sorry about that."

I silently reappraised my recent thought about 'only insertion'. So where were we now? Fifth base? Sixth?

Eddie looked back for the first time; he was easily the shyest of the four of us, and he gave my sister and me a perplexed look... just as Shayla settled back down, taking all of my cock into her pussy yet again. And now there was no question: she'd committed herself to fucking with me (in a good way). And for my part, my only real issue had been how she felt about doing this, so... Game On!

"Ooooooooh, mmmmmmmm, hey sexy," Shayla smiled into Eddie's shy face, using her flirtation with him as an excuse to issue a moan that was really because she was once again sitting completely down with her brother's cock buried in her pussy... although her flirtation was also sincere... she just loved flirting with and teasing my friends... exerting the power she had over them.

Shayla leaned forward a little to flirt with Eddie some more, raising her pussy just a little... leaving my cock still over halfway inside her.

"H-h-hey back?" Eddie stammered, then instantly jerked his head back to face the road.

Shayla lowered herself back onto my cock, and I made it twitch deep inside her. She leaned forward again, and asked Steve from about two inches away from his right ear, "How long until we're there, sugar?"

"Five minutes," Steve said. "Give or take," whereupon Shayla sat back down on my cock, and I realized she was fucking me... well, slyly fucking me.

Sitting back up, she said, reaching her hand between the two seats, "Well, drive safely, Mr. Chauffeur. Tonight we're getting you boys laid."

"What?" Steve gasped, as Shayla wigged her ass slightly, which I took as an invitation to begin fucking her steadily.

I glanced over at Baker who was staring at my sister, made sure the box would hide my actions, and I began slowly fucking.

"Yeah, there'll be lots of sexy, drunk-ish girls there," Shayla said. She then looked admiringly at Baker and said, "And if you other guys are as well hung as Baker here, I'm certain you won't have any difficulty in getting one of my cheerleader friends to suck and fuck you."

"Oh my God," Steve said out loud, as I continued slowly, surreptitiously, fucking my sister... wondering if she would... and could... really set these guys up with her hot friends.

"Would you?" Baker asked... he and Eddie both virgins. While Steve had hooked up with a girl named Beth a few times.

"I'll get you guys into the party," Shayla explained. "After that, you'll have to turn on your charm."

"I can do that," Steve said.

"I don't know if I can," Baker said, not a very confident young man.

"Oh, I think you can, big boy," Shayla reassured him as I kept slyly fucking my sister... wondering how long we could get away with doing this on the sly.

"I don't know," Baker said doubtfully, as she settled back down, again sitting firmly on my cock.

"You're so bad, big brother," she whispered ever so quietly, her hot breath tickling my ear as she slyly began grinding her hips and slowly fucking herself on my cock.

"As are you," I whispered back, still in awe of what was happening... and what had begun as some silly flirtatious play, then had shifted to an accidental insertion (at least on her part), had now become some very purposeful and willing incest on both of our parts.

"We don't have much time," she whispered, and she braced both of her hands on the back of the driver's seat while slowly fucking me.

I couldn't believe this was happening! My hot cheerleader twin sister with a college boyfriend... was willingly fucking me!

I knew I wasn't going to last long if she continued slyly moving her hips back and forth. I didn't think I should come inside her. Yet if she kept doing whatever she was doing with her pussy... which somehow seemed to be flexing its grip around my cock... I was going to explode, and thus do just that!

"Mmmmmmm," Shayla moaned as she continued slowly grinding on my cock... seeming to be getting close herself. After a minute or so of sweet... soothing... sly... grinding, she said, "Your driving is so sexy, Steve."

"It is?" Steve asked.

"Yes, it actually turns me on," Shayla moaned, obviously trying to hide what she was really doing behind some more excessive flirtation.

"It actually does?" Steve asked, perplexed, looking into her face via the rear view mirror.

"Yeah, there's nothing sexier than a man taking control," Shayla said, wiggling her ass.

I figured that was her sly, silent way of telling me it was my turn to do the fucking.

"What I mean is someone who just takes what he wants," Shayla added, actually turning around to glare an insistent look at me, since I hadn't yet taken what I wanted by resuming to fuck her.

"I can be that man," Steve offered, oblivious to what was happening directly behind him.

"I just bet you could," Shayla moaned sexily, while I lifted up my hips to fill her.

Steve suddenly slammed on the brakes, and Shayla was thrown forward, but then fell back onto my cock and landed hard, screaming, "Fuuuuuck!"

"Ohhhhhhh," I moaned, reaching new depths in my sister's pussy.

Baker looked over, so I squeezed my sister's left leg to warn her... since there was no way he could see anything that hand did.

"Sorry, a deer jumped out in front of us, and I almost hit her," Steve explained.

"You scared the shit out of me," Shayla complained.

"Yeah, and then you slammed right down on top of me," I added.

"Oh, dearie me! Did I hurtie your little wee-wee?" Shayla asked in a teasingly 'widdle' baby voice, but she was also wiggling her ass delightfully on my deeply imbedded dick.

"You did something, anyway," I joked, as Steve got us back up to highway speed.

Baker said, likely the bravest thing he'd ever said, "You can sit on my lap if you want?"

"I think we already know you couldn't handle that, Mr. Sharpshooter," she teased, and she leaned over and squeezed his dick again, which was still hard.

As she did, I turned slightly sideways and began fucking her harder... not crazy fast like I wanted to... I couldn't allow any sounds of my slamming into her... but still hard enough to stimulate both of us better than before.

"You're still hard, big boy," she said to Baker, as she allowed me to fuck her freely.

"Y-y-yeah," Baker said, clearly in awe that this hot cheerleader was touching his dick... again!

"What would happen if I sat on your lap, sexy?" Shayla asked with a soft moan, as I fucked her as smoothly as I could, given the awkward position and situation we were in.

"I-I-I don't know," he stammered, obviously overwhelmed by the unaccustomed attention he was receiving.

My balls were beginning to boil, and I knew I wouldn't last much longer.

As if reading my mind, my sister said (to Baker, thank God, not to me), "I bet you'd just erupt all over me!"

"Ooooooh," Baker groaned.

"Are you going to come again now?" she asked, still rubbing his cock through his costume.

"Yesssssss," Baker moaned, and I took her question to him as permission... as her moans increased...although she hid the real cause by teasing Baker.

Shayla turned to me and gave me a nod, which I took as permission to come inside her, knowing I'd only have a few more strokes in control before exploding, as she added, in reality speaking more to me than to Baker, "Yes, and I bet you'd come inside me, if we were actually doing it."

"Oh, God," Baker groaned, looking like he was about to shoot another load into his costume.

A few more strokes, and I was done. I wanted to moan, but I bit my lip to control any obvious sound that would give us away, as I erupted inside my sister's pussy.

"Yessssss," Shayla moaned loudly, while I filled her, and she rubbed him furiously.

"Fuuuck," Baker grunted, as he came too.

Shayla fell back against me... her body quaking as much as mine was... and I was sure she'd just orgasmed from my coming inside her.

"So hot," Shayla moaned, looking soulfully at Baker while her body quivered against mine.

"I think Shayla should join us in the front seat on the way home," Steve said, as he slowed way down and pulled up to a farmhouse.

"Oh? What would you want me to do up there?" Shayla asked playfully, as she leaned against me and recovered from her orgasm.

"Anything you like," Steve said, a lot more suave than Baker.

"Oh, really?" she asked, and the car came to a stop, while both of us recovered from the crazy orgasms we just gave each other.

"Yeah," Steve said, looking into his rear-view mirror.

"Could you guys stop hitting on my sister?" I complained, having ordinarily put a stop to it within the first few seconds, when I wasn't being distracted by... you know... fucking my sister.

"Too late for that," Steve said.

"Yeah, it's not my fault all your sexy friends want to fuck me," Shayla said, slyly wiggling her bare ass against me... my cock still buried inside her.

"So... we're here," Steve announced.

"Well boys, have fun," Shayla said. "I may need a ride home, so don't take off without me."

Eddie got out of the car, and Baker, sheepishly, did too, as Shayla climbed off of me... her wetness and mine dripping onto me, as her ultra-short skirt automatically fell into place as if nothing scandalous had just happened..

I quickly snapped my costume together inside the dark car, then I too got out... my cock still hard.