We Need to Study Our Math

"Goddammit!"

The curse slipped out under my breath—but not as far under my breath as it should have been.

"Careful, Mase." my twin sister whispered. "Mom or Dad might hear you. And you know what happens when they hear us talk that way."

I looked her in the eyes. "Yes, Madison, I know," I said. I was whispering quietly now, though I was still upset—upset enough to have used her full name. "Sorry. But this problem shouldn't be so hard. What am I not seeing?"

It was a little after eleven on a Saturday night near the end of January—late, maybe, but not too late for a night when there was no school the next day. In fact, even though Mom and Dad had gone to bed an hour and a half earlier, it was still early enough that you might ask why a brother and sister—a couple of eighteen-year-old twins, high school seniors—were sitting in their mom's kitchen, studying calculus instead of being out partying and trying to get laid before curfew.

The answer to that one is easy: we were taking calculus; we had a test on Monday; and we had gotten Cs on the last test because we had dicked off for a few weeks. We'd managed not to let Mom or Dad find out about that, so it wasn't because we'd been grounded that we were studying on a Saturday night. But if we didn't do pretty well on this exam and the next, there would be no way to conceal a semester grade that was—shall we say, "less than optimal.". And then, for sure, the fecal matter would experience a collision with the rotating air circulation device. And, in consequence, we would find ourselves in the headwaters of the proverbial polluted tributary, lacking the proper means of propulsion.

"Which one?" she asked. She leaned over from where she was sitting next to me at the kitchen table, and I moved the book toward her to show her the problem.

"That's an integration-by-parts problem," she said. "It isn't very hard at all."

"I tried that," I answered. "But I couldn't make it work. What am I doing wrong?" I showed her my scratchwork. She leaned over to look at it; a boob rubbed against my arm as she did. The mound of flesh was distracting, but, somehow, I maintained my focus on the problem.

"You stopped too soon," she replied. "This is one of those problems where you have to repeat it a couple of times."

The technique came back to mind. "Shit!" I said. "I should've remembered that trick."

She punched my upper arm. "Not so loud, Mason," she growled in a stage whisper. She was a little pissed, now, that I needed a second warning about noise and bad language. "If they hear us, we'll have to explain why two healthy eighteen-year-olds are so worried about their calculus that they're studying it on a Saturday night instead of being out trying to do things they don't want their parents to know about."

They'd been upstairs in bed for a while, so they had no idea that we were still up, still studying. We hoped they were asleep, but there was no guarantee. She went on, "But first, you'll get grounded for saying 'shit.' What's wrong with you tonight?"

"I don't know, Maddie" I said as I started working out the problem that had been frustrating me. "I guess I just don't like having to stay in and study tonight."

"Okay," she said. "I get it. I don't like it either. It's boring. This sure isn't the way I want to spend Saturday night. Let's each do a few more problems and then take a break." She got up from the table where we were sitting and, carefully and quietly, pulled a pan out of the cupboard. "I'll put on some water for cocoa, and we can each have a cup while we think about other things for a little while."

"That works for me," I said. "Then maybe we can study for another hour or so before we go to bed."

"I was thinking of hitting the hay around one," she said, as she ran water into the pan.

I thought about it as she put the pan on the stove and got two cups out of the cupboard. "Sounds good," I agreed. "Cocoa, study until one, and then bedtime."

She grunted in agreement as she put a spoonful of mix into the second cup.

She reseated herself and I went back to my problem—and had that one and the next two worked out before the water boiled. The one that had stumped me had been easy, like she'd said—once I remembered the trick.

The two that followed were just as easy, using the same trick. I got them both done in the time it took her to leave the table, get a pot holder out of the drawer, pick up the metal-handled pan, pour hot water into the two cups, and give them each a stir.

I was just finishing that last problem when she came back to the table, a cup in each hand. She put her own down where she had been sitting and moved to place mine where I could reach it. As she leaned over, a boob pressed into the back of my shoulder again. This time, I couldn't resist the urge to wiggle against it.

Feeling my motion, she snorted "Are you perving on me, Mase?" And she pressed a little harder, imparting some motion to her tit as she did so.

"There's nobody else to perv on around here," I said, "so I don't have any choice."

After a final fillip, she pulled away from me and delivered another punch. "What about Mom?" she asked.

Mom was over forty, so she was ineligible—at least in my mind.

"Eww!" I groaned. "You've got to be kidding."

"You mean I'm your last resort?"

While this was brother-sister repartee, there was a hint—that I didn't immediately hear—of pain in her voice. "No," I said, after I'd taken a sip of my hot chocolate. "You're my only resort."

"I suppose," she said as she sat down beside me again, "I should be happy that at least I'm a resort!'

"Hey!" I replied, finally hearing the unpleasant note in her voice. "That doesn't sound like you. What's wrong?"

"Oh," she said, "nothing too terrible. It just isn't working with Gene. I like him, but I don't think it's going to last."

"Gosh, I'm sorry," I said. I took another sip. "Do you want to talk about it?" Gene was a guy she'd been dating for a few weeks.

"A little, I guess. But it isn't worth a lot of your time. He just isn't the guy I thought he might be. Probably time for me to move on." She brought her cup to her mouth and took a sip—too big a sip: she winced from the mouthful of hot liquid. "Ooh! That's still too hot!"

"Are you okay?" I asked. "Need some cold water? An ice cube?" I moved to get up.

She put a hand on my thigh and pressed downward, shutting down my motion before I was off the chair. "No," she said. "It was just a little too much. I'm okay."

We sat there for a minute or two, saying nothing, sipping on our cocoa. Then she broke the silence. "I think he's gay. But he hasn't figured it out yet. He hasn't made a move on me during the four weeks we've been dating. Even when I 'accidentally' rub against him. He never even kissed me until last week."

Pointedly, I scanned her body with my eyes. Like me, she had light brown hair and blue eyes. At about five feet, four inches, she was seven or eight inches shorter than I. We were both slender and moderately athletic. Her boobs were prominent, though not exaggerated; we differed in that respect. She had nice hips and a well-rounded ass. (I didn't have those, either.)

All in all, and even in the loose, flowing sweatshirt and sweatpants she was now wearing, my male eyes found her very pleasing. Admittedly, those eyes belonged to a pretty horny male: I didn't have a steady girlfriend, and I dated around. It'd been a few weeks since I'd gotten any action—let alone gotten laid.

"Yup!" I offered. "If he hasn't been trying to get your clothes off, he's gay. Gotta be!"

I sipped my cocoa. She smiled at the compliment. It was a subdued smile, but it was a smile. And, I noticed, her hand still rested on my thigh. "Thanks," she said. "But twin brothers aren't supposed to notice. And when one does, it's probably because he's trying to cheer his sister up."

"Well, I guess I am trying to cheer you up. But you're definitely hot, so wanting to make you happy isn't why I said it. It must feel awful to be with a guy who doesn't seem to be interested."

"Well, it doesn't feel all that good," she said, as she drew another sip from her cup. "But I'll survive. Maybe other guys will be interested." The hand on my thigh delivered a squeeze—and remained where it was.

"They will!" I said. "You can be sure of it."

The cocoa in both cups was gone now. The hand finally left my thigh. But as she removed her hand to reach for my empty cup, it brushed against my cock, delivering what I might have called a feel—or even a caress—if I hadn't thought it an accidental consequence of her other motions. Picking up my cup, along with hers, she stood. As she moved toward the sink ten feet or so away, cups in hand, she said, "Thanks. But we'd probably better get back..."

As she reached the sink and set the cups down beside it, she let the sentence hang. She turned and looked into my eyes. There was a peculiar expression on her face.

"What..." I mumbled, not sure what was on her mind.

"Just..." she mumbled back. "...I was just thinking..." And as she again slowed to a stop mid-sentence. Her hands drifted to the hem of her sweatshirt. "Oh, what the fuck!" she said under her breath, and in a single motion she upended the sweatshirt, pulled it over her head, and threw it aside.

I think she was smiling at me, but I'm not sure, because my eyes were riveted to her light blue bra and the boobs it now emphasized. "What're you doing?" I said—loud enough for her to hear, but not so loud that there was any risk of Mom or Dad hearing. Stunned, almost stupified, by her action, I began, "You can't... ." But I ran out of steam before I could tell her what she couldn't.

"I think I can!" she answered in her own whisper. I stared, goggle-eyed, jaw practically resting on my chest, as she faced me and, in that peculiar contortion I'd seen a girl perform only two or three times before, reached behind herself to unhook her bra.

Seconds later, she shrugged out of the bra and stood facing me—proudly displaying her tits. That is, I hope she was proud of them; she should have been. But if my attention had been riveted to her bra earlier, it was welded to her boobs now, so I didn't notice her face.

She stood there and my mind reeled. I stared wordlessly, mouth agape. They were lovely, as I had always suspected. (I'm not going to pretend that I'd never wondered.)

I shouldn't be looking, I knew, at what she was showing me. But I couldn't help myself. I was so entranced that I didn't notice that her hands were still busy. That is, I didn't notice until—having untied the drawstring—she allowed her sweatpants to slide down over her hips and fall to her ankles. She took a step forward; they fell off her feet to the floor and remained behind her.

She stood there, wearing only a pair of white socks and her tiny panties—tiny, pale, pink, bikini panties. My eyes dropped reflexively to them and the shapes they covered. The cloth was gossamer, only nominally opaque, and I could easily discern the cloud of dark hair that covered her mound. That nether hair was darker than the hair on her head.

Both the panties and the shadowed nook between her thighs still concealed most of the mysteries I now wanted to explore.

Not only, I knew, should I not look at my twin sister's boobs, but I shouldn't want to see more of what was now, almost, on display, And I definitely shouldn't get a hard-on over her body. But I looked, I wanted, and, boy, did I harden. I stared, unable to help myself or my cock's reaction.

Her hands went to her panties; she hooked her thumbs into their waistband.

"No! "No! You can't!" I'd found my tongue, finally. Somehow, I managed to say it quietly; Mom and Dad were still upstairs (asleep, I hoped) and I understood that—whether I wanted her to continue or not; whether she did continue or not; whatever this might, or might not, lead to—attracting their attention now would not be a good idea.

"Maybe I can't," she whispered back to me, "but I'm going to!" And she slowly straightened her arms.

Time slowed to a crawl. Unable to help myself, I watched in fascination as the upper part of the panties folded, then wrinkled, and finally collapsed under the increasing pressure her hands exerted on it. The garment slid downward, first to reveal creamy skin. An island of pubic hair peeked over the pink upper rim, emerging little by little.

I made another valiant effort: "Don't you think...", but I stopped there as the top of those descending panties moved to reveal the head of her cleft, shrouded by dark curls of hair. Reluctantly, it seemed, the panties pulled away from her body, and I saw into the alcove between her thighs; hair and shadow still concealed much of what I knew I should not, must not, want to see. There was a surge in my pants as my cock reacted to what was now so nearly in sight—what it most wanted me to see.

When her panties had reached mid-thigh, she withdrew her thumbs. The scrap of pink fabric dropped loosely to the floor. She took a step toward me. Another step, and the panties slid over her feet to stay behind. My eyes remained glued to her pussy.

She stood in front of me now, completely and gloriously naked, six or eight feet away. "What do you think?" she asked. "If you'd been dating me for a month, would you be trying to get at it?"

"Hey!" I said. "I'm a guy. And I'm not gay. And, like I said, you're hot. So, sure!" Now that I'd found a subject other than what she shouldn't be doing, I wasn't having so much trouble talking. That didn't stop me from continuing to stare, though. "But I could have told you that without..." My tongue got tied up again now that I was back to telling her what she shouldn't be doing.

I failed to complete the sentence; she took another step toward me. "I can see that you're interested," she said. "You're gawking." She took another step.

"Guys don't get to see what you're showing me," I offered, lamely. "At least, not very often."

She kept moving.

By the time I'd finished the statement, she was within arm's reach, and all I could see of her pussy was the uppermost reaches of her bush. Deprived of the view I'd had of her most intimate parts, I focused instead on her boobs. They were, I decided, almost as interesting as her pussy had been—especially because they were in full view, and her pussy wasn't.

"Not an excuse," she said. "You aren't supposed to stare at your twin sister. Even when she's naked. Especially when she's naked."

Her remarks had to have been verbal teasing added to the visual teasing that belied her words; I was too preoccupied to pick up on that. "But—" I began a confused reply. She interrupted me by reaching forward and grasping my cock through my jeans. It was now fully hard and must have been an easy target.

"Hmmm." She said it almost clinically. "You are interested." And she emphasized her observation with a couple of caresses. Involuntarily, my hips responded—thrusting my cock into her hand and pulling it back. She continued: "Much more interested than a brother is supposed to be!"

She stroked half a dozen more times before saying, "Let's take a look!"

She reached for my zipper. In spite of my stuttering efforts to tell her to stop, she soon had the zipper open and fished inside. But not for long. She had no trouble finding my cock (It certainly wasn't making any effort to hide!), and pulling it out into the open.

"Nice!" she observed, as she looked directly at it and stroked it a bit more.

I was completely off balance, now. Not that I had any objection to having a girl handle my boner, but this girl was my sister!

In spite of the stroking, which was more than a little distracting, I was beginning to regain my equilibrium. I began, in the little piece of my mind that I had managed to get under control, to try to think of a way to put an end to this. But she had other ideas. Before I could arrive at anything, she was on her knees in front of me. She licked the head of my cock.

That cost me what little I'd regained of my composure; my hips responded with a reflexive thrust. The reaction took me by surprise, but she seemed to have expected it, because half the length of my cock slid into her mouth, eliciting only a subdued "Mmmm," and she began bobbing her head forward and back, forward and back.

The new sensations unhinged me again. Her motions evoked more thrusts from my hips. I recall thinking "I can't let my twin sister give me a blow job!" But I couldn't have been quite right, because my twin sister was doing exactly that, and I made no effort—and had no desire to make any effort—to stop her.

Lost in sensation, I didn't notice that she was undoing my belt buckle until she placed both her hands on the waistband of my jeans, removed her mouth from my cock, and pulled down both jeans and undershorts.

"We can't..." I forced out.

"We can," she replied as she stood up and moved up against me. My cock, slippery from the moisture of her mouth, slid up her belly, and her boobs pressed against my chest. Automatically, my arms wrapped themselves around her. "You feel good against me," she whispered as she pressed her body against me.

My cock throbbed at the pressure of the naked female body against me; and, without thought, I replied, "So do you!" Meanwhile, my pants took the opportunity to slide down to my ankles.

Unthinkingly, I sought her mouth with mine. I found it, and our tongues intertwined. My cock throbbed where it was trapped between our bodies.

Much as I liked feeling her naked body against my own, I wasn't sure that I liked where this seemed to be going. But I was far from sure that I didn't like it, either. I held her tightly, pressing her willing body against myself as the kiss extended. Each second it lasted, my doubts receded a little further. The smoky odor of her hair filled my nostrils, and, in spite of myself, I found that I was maneuvering her backward toward the table where we'd been working so that she could sit on it and spread her legs for me.

She was thinking along the same lines; when the edge of the table pressed against her, she hitched herself up an inch or two, without breaking our kiss, and rested her weight on it. As she sat, she parted her thighs to give me the access I so wanted.

I pressed forward; my cock skated upward over her mound, and my balls came to rest against the heat and moisture of her cleft. She shimmied against me.

Now my desire had overcome my good sense and driven away every urge to resist. I had no doubt about what we were about to do. I was about to fuck my twin sister.

And she was going to fuck me right back.

Pulling an arm from where it was wrapped around her so I could grasp my cock, I pulled back from our kiss and looked downward. My hips retracted, and my cock slid back over her mound so I could see her pussy. I placed my tip between her outer lips, poising it to part her inner lips. I pressed forward a bit, and felt myself engage her entrance. The hot wet kiss of her channel's opening on my glans was a foretaste of the raptures ahead.

In eager anticipation, I paused to set myself for the thrust that would embed the length of her twin brother's cock in my sister's pussy.

The smoke alarm chose that instant to go off.

To be continued.