I Followed My Sister and Saw What I Shouldn't Have Seen

My name is Mateo. When this happened, I had just turned twenty. My sister Laura was twenty-four and had been with her boyfriend Sebastián for four years, a good-natured guy with whom they already had a wedding date set. They didn’t have much longer to go.

Laura and I were never especially close. The age difference had created between us that polite distance of people who share blood but not much else: Sunday meals, the occasional birthday message, courtesy questions about school. My friends, whenever they saw her, told me bluntly: my sister was hot. And it was true. Laura was dark-haired, the kind of dark that comes from the sun since childhood, with long wavy hair and a figure that didn’t need anyone’s help to turn heads. I was more ordinary: tall, with features that didn’t stand out much, the kind of face people forget the moment you turn away.

With Sebastián, on the other hand, I did get along well. He was five years older than me and had that kind of patience that seems to come from having lived through things. He took the time to ask how school was going, to invite me for a drink when we crossed paths, to treat me like someone whose opinion mattered. He was, without any complications, a good guy. Which makes all of this harder to tell.

That Friday night I went out with some friends to a bar in the neighborhood. We’d been there a couple of hours, between music and drinks, when Tomás nudged me.

—Isn’t that your sister over there?

I turned around without giving it much thought, expecting him to be mistaking her for someone else. But he wasn’t. Laura was at the back of the place, wearing a black dress I’d never seen on her. Her hair was loose, her eyes made up. She was dancing pressed against a man who wasn’t Sebastián, and the way that man had his hand on her waist was not the way someone touches a girl they just met that night.

I kept staring. Laura didn’t see me. For a moment she rested her head on the guy’s shoulder, then pulled back, then leaned in again. He whispered something in her ear and she laughed in a way I didn’t know from her.

What was strange wasn’t just that she was there. What was strange was that that night, as far as I knew, Laura had dinner with friends somewhere else in the city.

My friends wanted to move to another place. I made up a headache and stayed.

***

At midnight I saw them leave together. They walked down the sidewalk talking in low voices, holding hands, with that familiarity of people who already know exactly what they’re going to do. I followed them from a distance, close to the doorways, feeling ridiculous and unable to stop.

When I saw them turn into the street where Laura and Sebastián’s apartment was, something tightened in my chest. I knew that building. Months earlier, Sebastián had given me a set of keys “for emergencies,” with the seriousness of someone doing you the honor of trusting you. Those keys were in my jacket pocket that night for no special reason, because I hadn’t bothered to take them out.

I moved ahead. I opened the front door before they arrived. I ran up the three flights and went into the apartment without turning on the lights. I knew the layout of the living room almost as well as my own. I slipped behind the big curtain at the back, that dark fabric curtain Sebastián hated and Laura refused to take down because it was “decorative.” I stayed still, my heart pounding harder than necessary.

I heard them come in two minutes later. Laura’s voice, low, with a laugh I didn’t know. The guy replying something. Footsteps, a rustle, the sound of a long kiss.

—We’re alone here —she said.

***

When they turned on the living room lamp I nearly stopped breathing.

Laura had taken off her coat and was letting herself be kissed in a way that left no doubt about what both of them wanted. His hands moved over her back, her hips, the edge of the dress. She was unbuttoning his shirt slowly, without hurry, with a focus that somehow disturbed me even more than anything else.

The guy—Cristian, I heard her call him that—slid her dress straps down. The fabric fell to the floor. Laura had on underwear that clearly wasn’t for everyday wear, and that detail hit me in a strange way: it meant she had planned this. That she had gone to that bar intending to end up exactly where she was ending up.

I stayed motionless behind the curtain, holding my breath, while my sister—my sister who in a few weeks was going to get married—let that man touch her without the slightest resistance. Cristian slid his hands under her bra and squeezed her tits hungrily, digging his fingers into her brown flesh while Laura let out a short moan, the kind that slips out when something lands right in the center of the body. He sucked her neck, her jaw, and she tilted her head to the side to give him more room, opening her throat as if she wanted him to keep going.

Cristian sat her on the sofa and knelt in front of her. Laura spread her legs and let him pull her skirt up to her waist. The fabric bunched at her hips, and underneath appeared the tiny edge of her black panties, already soaked at the center. He ran his tongue over the fabric first, slowly, pressing his mouth right where she was trembling. Laura leaned her head back and closed her eyes. The sounds were low at first, then more direct, less filtered. Then she got on her knees and returned the favor: she undid his belt, opened his pants, took his hard, thick cock out with a steady hand, and sucked it without playing games. She licked his glans, sucked the shaft, took him all the way to the back of her mouth with that obscene rhythm that makes a man lose his composure in minutes. Cristian grabbed her hair, but not painfully, guiding her to take him deeper and deeper while Laura breathed through her nose and kept going, swallowing his cock as if she were truly testing it.

I’m not going to lie about what I felt. It would have been easier if I had only felt disgust, or indignation, or the clean rage of someone discovering a betrayal. But there was something else there, harder to name: the tension of seeing something you shouldn’t see, of being unable to look away, of the body reacting before the mind has time to weigh in. I was ashamed. And I kept watching.

I touched myself without having decided to do it. It was mechanical and inevitable, and it shamed me while I did it and after.

Laura rose up, pulled off her panties with a quick motion, and ended up spread open on the sofa, wet, shining, with her cunt exposed and throbbing as if the skin itself were begging for more. Cristian stood up, stripped completely, and brushed the head of his cock against her entrance a couple of times, as if punishing her with the tip before pushing in. She held on to his shoulders and, as soon as the cock started sliding into her, let out a rough groan that made me clench my teeth behind the curtain. He opened her slowly, centimeter by centimeter, sinking into that tight cunt until his hips slammed against her pubis. Then he started fucking her with sharp, marked thrusts, making the whole sofa tremble. Laura dug her heels into his thighs, begged for more with a broken voice, told him not to stop, to wreck her right there, to make her come once and for all. Cristian answered with one hand on her waist and the other on a breast, fucking her with that measured violence only those who know how to listen to another body have.

Then he put her face down, arching her back, and took her from behind again. Laura braced her hands on the seat, ass in the air, face buried in the backrest, while he spread her cheeks and rammed his cock into her from behind, over and over, until every slap sounded wet, obscene, full. She was moaning louder now, her voice muffled between her teeth, clinging to the sofa as if they were taking her apart. Cristian spit between her buttocks, rubbed her clit with two fingers and made her tremble all over, writhing with pleasure while he kept driving into her without easing up.

I don’t know how much time passed. I only know that, when I noticed he was tensing up, when he started breathing harder and letting out those animal grunts at the edge, Laura turned to look at him, mouth parted and face red. She sat on top of him without letting him pull out, took him all the way back inside, and started riding him furiously, bouncing on that hard cock as if she wanted to wring everything out of him. She grabbed his face, kissed him hungrily, and at one point Cristian took her ass in both hands and squeezed so hard she cried out.

Then yes, he came. I saw it in his face, in the tension in his stomach, in the way he held her while his cock throbbed inside her. Laura didn’t move away. She kept him inside, feeling him fill her cunt with cum, while he let out a hot load that made her shiver. She kept moving her hips to milk him to the end, as if she wanted to squeeze out the last drop. Then she stayed still for a second, breathing fast, her body still mounted on him and the wetness spilling between her thighs.

When it was over between them, the two of them stayed still for a while. They murmured things I couldn’t understand. Then Cristian started getting dressed.

I took advantage of that moment. I pulled out my phone and dialed the number of the apartment’s landline.

It rang once. Twice. The effect was immediate. Cristian froze, gathered the rest of his clothes at top speed, ignored Laura asking him not to leave, and walked out the door without looking back. He knew exactly what was at stake.

I heard the shower running. I sat on the armchair, on the opposite side of the sofa, and waited.

***

Laura came out of the bathroom with a towel wrapped around her and wet hair. She saw me and the color drained from her face.

—What are you doing here? —she said, hard-edged.

—I had Sebastián’s keys. The emergency ones. The ones he gave me.

She processed that for a second. She tightened the knot of the towel.

—How long have you been here?

—Since before you got here.

Silence. Laura didn’t move from the hallway threshold.

—Mateo, you can’t...

—Do you want him? —I cut in—. Sebastián. Tell me.

—Of course I want him.

—Then I don’t understand.

—It’s complicated. You’re too young to understand it.

—I’m twenty. I’m not a kid. Explain it to me.

She crossed her arms over her chest and took a moment before speaking.

—Sebastián is the only person I’ve been with. The only one. And I wanted to know what it was like with someone else before I got married, before that was closed off forever. I didn’t want anything serious. Just one night.

—So he can’t know anything.

—He can’t know anything.

We looked at each other. I thought of Sebastián giving me those keys with complete trust. I thought about what I had done behind the curtain and wondered once again what kind of person I was.

—I’m not going to tell him anything —I said at last.

She let out a breath.

—Thank you.

—But I need to understand one thing.

I got up from the armchair. I approached slowly, without hurry. Laura didn’t move, though something in her posture changed: her arms a little less crossed, her eyes a little more open.

—You spent all night looking for something you don’t have —I said, a short distance from her—. And it never occurred to you to look closer?

Laura opened her mouth. It took her a moment to understand. When she did, she frowned.

—We’re siblings.

—I know.

—Mateo, that’s crazy.

—Worse than what happened tonight?

She didn’t answer. I sat on the arm of the sofa, beside her, without touching her. Just close. Waiting.

—You’re drunk —she said.

—Barely.

Another long silence. Laura stared ahead. Then she looked at me.

—What exactly did you see? —she asked, in a different voice. Lower.

—Everything.

She took that in. She held my gaze longer than would have been reasonable between two people who are only siblings. Then she lowered her eyes for a moment, raised them again, and the knot of the towel came loose on its own, or almost.

***

What happened after that I’m not going to detail in full. I can say that Laura was nothing like what I would have imagined if I had been the kind of person who imagines those things about his sister. She was direct, no detours. She knew what she wanted and asked for it with her hands and with her voice, without apologizing. At one point she took my face in both palms and looked at me fixedly, as if making a decision she knew had no way back, and that look was more intimate than anything else that happened that night. She kissed me with a mouth still salty from her ragged breathing, pushed me against the sofa and climbed on top of me without taking the towel off completely, opening it just enough to let me see her heavy tits and her belly shining with sweat. Her skin smelled of soap, of recent sex, of that heat that lingers when someone has just come and already wants something else.

I untied the towel and it fell to the floor. Laura stood naked between my legs, all curves and fixed gaze on mine, as if daring me to back out. I didn’t. She pulled down my pants, took my hardened cock out and brought it to her mouth with brutal naturalness, licking the tip, sucking with the same hunger she’d used on Cristian’s. She looked up at me while she sucked me off, taking more and more of me deeper, until saliva ran down her chin. I held her hair, made her set the pace with her tongue and the hollow of her mouth, and when I pulled out she licked the head again before straddling me.

Laura settled on top, guided my cock to her entrance and let herself sink down slowly, opening around me with a long, tense moan, as if her body were surrendering at the same time as her mind. I felt her cunt clamping around me in waves, wet, hot, taking me all in. She started moving without waiting for any instruction, bouncing first softly and then harder, digging her nails into my shoulders as she leaned down to kiss my neck, my mouth, my jaw. I grabbed her by the waist and lifted her a little to fuck her better, driving in deeper, pulling dirtier moans from her. She asked me to take her hard, not to let up, to fill her, and I answered with short, deep thrusts, feeling every wall of her cunt squeeze around my cock.

Then I turned her and laid her on her back on the sofa, legs open and ass at the edge. I lifted her hips and entered her from behind again, slowly at first, then with more rhythm, listening to the wet slap of our bodies. Laura buried her face in the cushion and moaned without restraint, repeating my name in a voice I had never heard from her. When I touched her clit with my fingers, she arched suddenly, shuddered all over, and soaked my hand. Then I lifted her again, sat her on top of me, and made her come again while I myself held on the verge of bursting, feeling my body pounding from my abdomen to my thighs.

Afterward we lay there on the sofa, the lamp still on, the sound of traffic slipping through the half-open window.

—Sebastián can’t know anything about this —she repeated, in a low voice.

—I know.

—And this can’t happen again.

She said it with conviction. I didn’t answer, because there are things people say at certain moments and life later decides whether they were true or not.

The first part held. Sebastián never found out. The second, however, lasted as long as promises made when you still have someone’s heat on you: very little.

I can’t quite explain what remained between Laura and me after that night. It wasn’t the kind of love you plan. It was something else: the weight of a shared secret, the attraction that doesn’t disappear just because one decides it should. Every time we were alone, at some family visit, in some calendar slip, something imposed itself between us that neither of us had asked for out loud and that both of us made easier without saying so.

Laura married Sebastián. I went on with my life. And even so, from time to time, when time and circumstances allowed it, we found ourselves in that nameless space neither of us had designed but that both of us had, in some way, chosen not to destroy.

I don’t know if that’s right. Probably not. But I also don’t know how that night would have ended if I hadn’t followed Laura down the street, if I hadn’t opened that door, if I hadn’t stayed still behind the curtain waiting for the lights to come on.

Some things happen because you don’t stop them. And sometimes, those are exactly the things that matter most.