My Sister-in-Law Used an Excuse to Get into My Bed

Lucía had arrived at the house at the beginning of summer, when her parents set off on a three-month cruise. Damián and Carolina welcomed her without giving it much thought: she was Carolina’s younger sister, newly twenty, and needed somewhere to stay while she finished taking care of some university paperwork.

What none of the three imagined was what living together would awaken beneath the roof of the apartment in Rosario.

Carolina left early. She worked in the management office of a downtown bank and came home after seven, exhausted, with no desire for anything but bed. Damián, on the other hand, set his own hours: he was an electrician, and many afternoons he spent at home waiting for the next job. Those afternoons, alone, with Lucía wandering around the living room in barely any clothes, became a silent torture.

Because Lucía knew exactly what she was doing. Of that he was certain. The way she bent over to reach for something, the thin T-shirt with nothing underneath, the looks she held for one second too long whenever her sister wasn’t there. He kept telling himself it was his imagination, that she was his wife’s sister, that it shouldn’t even cross his mind. And yet it crossed his mind all the time.

***

It happened one January afternoon, with heavy, humid air clinging to the skin. Damián was sprawled on the couch with a beer, pretending to be interested in a game. Lucía appeared from the kitchen wearing denim shorts so short they barely covered her thighs and dropped down beside him with a long sigh.

—Brother-in-law —she said, biting her lip—, you have to help me with something. I feel weird about it.

—What happened? —Damián lowered the volume without really knowing why.

—I’m itchy everywhere… down there. Since last night. I don’t know if some bug bit me or what. —She scratched herself through the fabric without a trace of modesty, glancing at him—. I’m embarrassed to go to the doctor. Can’t you take a look?

He choked on the last swallow. This isn’t happening. But his body was already answering before his mind could: an uncomfortable pressure against his pants, his pulse pounding at his temples.

—Lucía, I don’t think…

—Just look. One second. If it’s a bug, you can tell me and that’s it.

He didn’t know when he said yes. Maybe he didn’t say it in words. Lucía lifted herself slightly from the couch, yanked down her shorts—she wasn’t wearing anything underneath—and sat down again, spreading her legs toward him.

The air caught in his throat. She was shaved, the skin a little reddened in the folds, and there was a sheen of moisture that had nothing to do with any itch. The scent of heat and skin reached him full on.

—Here —she whispered, pointing with one finger—. Do you see anything?

Damián leaned closer. He made a show of examining her, as though he were really looking for an insect bite, but his hand no longer obeyed the excuse. He placed two fingers against the inside of her thigh and felt her skin break out in gooseflesh.

—I don’t see any bug —he said, his voice deeper than he intended—. It’s a little irritated, that’s all.

When his fingers brushed against her parted lips, Lucía let out a low sound and pushed her hips forward. She didn’t pull away. Quite the opposite.

—Touch me a little more —she asked—. It burns right there.

***

What came next had nothing medical about it. Damián parted her folds with his thumb and found her already slippery, ready, indecently wet, leaving his fingertips drenched. He began to stroke her slowly, from bottom to top, first sinking in only the tip and then going deeper, until his finger slid inside without any effort. She arched her back against the couch and dug her nails into his forearm.

—That’s it, brother-in-law, that’s it… Don’t keep me waiting.

He worked her with his hand, pushing his finger in and out with an increasingly confident rhythm, his thumb drawing slow circles above, searching for the exact spot that made her gasp. Lucía breathed through her mouth, her cheeks flushed, her hips following the movement of his hand as though she were riding him. Damián lowered his head and kissed her exactly where his fingers were, tasting the salty sweetness of her arousal while listening to her moans grow louder.

—That… yes… touch me harder —she murmured, her voice in pieces.

One finger wasn’t enough for him. He pushed in two, slowly at first and then with greater determination, opening her with his firm palm and soaked knuckles. Lucía shuddered all over, her legs spread without shame, her shorts already forgotten on the floor. Damián held her gaze when she bit her wrist to keep from screaming, then leaned in again, licking her, sucking her clitoris with filthy, insistent patience until he felt her trembling beneath his tongue.

—Don’t stop —she begged, pulling his hair—. If you stop, you’ll fucking ruin me.

He lifted his head and undid his pants. The bulge hurt so badly his hands were almost shaking. Lucía slid down onto her knees between his legs and took him in both hands before lowering her head. Her hot mouth enveloped him at once, wet, swallowing him little by little while her tongue traced his shaft and tip. Damián gathered her hair into a fist, not to force her, but to watch her work, to see her cheeks hollow, to watch her swallow eagerly, her lips wet with saliva and pre-cum.

—Look at me while you do it —he asked, his voice broken.

Lucía raised her eyes without stopping sucking him. Drool ran from the corner of her mouth, and still she kept going, taking him all the way in, squeezing him with her tongue on every upward and downward stroke. Damián felt he wouldn’t last much longer. He pulled her gently up by the hair, sat her astride him, and yanked up her shirt, baring her small, firm, tense breasts, her hard nipples brushing his chest. She settled herself, gripped the back of the couch, and guided his tip to her entrance, rubbing herself against him for a moment until she had wet him completely.

Then she lowered herself slowly, inch by inch, with a muffled moan that became a long sigh when she had taken him all the way inside. They both exhaled at the same time. Damián held her by the waist and felt her gripping him from within, hot, tight, wet all the way to the base. Lucía threw her head back and began to move on top of him, slowly at first, sliding up and down with a friction that drew a groan from them both, then deeper, dirtier, pounding hard enough to make the couch creak.

—You’re leaving me wrecked —she gasped against his ear—. Keep going, keep going, don’t let me go now.

Damián bit her neck, lowered his hands to her waist, and met her from below, thrusting his hips upward with every stroke to drive himself deeper. He squeezed her ass, forcing her down completely, and Lucía answered with a loud, shameless moan, spreading herself wider and groaning his name through clenched teeth as she moved over him desperately. Sweat ran down their backs, their chests, their groins. The sound of flesh colliding mingled with her gasps and his grunts. Outside, the game continued, unheard by either of them.

—Harder —she taunted him, digging her nails into his shoulders—. I want to feel you breaking me open inside.

He turned her over onto the cushions and arranged her face down, spread her legs with both hands, and drove into her from behind, entering all at once to the hilt and making her arch her back with a muffled cry. Damián gripped her hip so he wouldn’t lose his rhythm and pounded her again and again, deep, with a filthy, heavy cadence that made her legs vibrate. Lucía rested her forehead against the arm of the couch, her lips parted, her ass raised and trembling with every blow. When he moved her legs slightly apart and slid a hand beneath her belly, he felt her contracting around his cock, squeezing him in increasingly powerful spasms.

—There, there… I’m coming —she moaned shamelessly, her voice breaking.

Damián slipped one hand between her legs and rubbed her clitoris with two fingers while continuing to thrust in and out, listening to her come undone. Lucía began to convulse beneath him, her knees trembling, her mouth open in a scream she muffled against the upholstery. He continued for a few seconds more, each thrust more brutal than the last, until he felt the final pull in his cock and came inside her with a growl, buried to the hilt, his forehead resting on her shoulder and his breathing broken.

They remained still, stuck together by sweat and semen, until reality returned all at once. Carolina would be home in a couple of hours.

—Thanks for checking my itch —Lucía said with a smile that had nothing innocent about it as she adjusted her soaked clothes.

Damián didn’t answer. He knew he had just crossed a line there was no coming back from.

***

The itch, of course, didn’t go away. The next morning, as soon as Carolina closed the door, Lucía appeared in the kitchen wearing an enormous T-shirt and nothing else.

—It’s still bothering me, brother-in-law —she said, leaning against the counter—. Will you take another look?

This time they didn’t even pretend. Damián set down his coffee, sat her on the counter, and spread her legs again, with the same urgency as the afternoon before and even more hunger. He lowered his head and explored her with his tongue, unhurried, licking her entrance first, then the swollen edges, then the exact spot that made her press her fingers against the marble. Lucía moaned without caring about the neighbors, her legs spread and her back arched, while he sucked her deeper and deeper, pushing in two fingers at the same time and thrusting silently until he heard her beg.

—That’s it, that’s it… don’t leave me like this —she stammered, trembling.

Damián ignored her. He ran his tongue over her clitoris until she was completely beside herself, held her by the ass so she couldn’t escape, and kept sucking, licking, and fingering her until he felt her grow even wetter. When she came, she climbed down from the counter, shoved him against the refrigerator, and took care of him with her mouth until the end, swallowing him without hesitation, one hand squeezing his balls and her eyes locked on his as she made him moan through a clenched jaw.

That was how the routine began. Every morning, as soon as Carolina left, there was a new excuse. Her back hurt and she needed a massage. She didn’t understand how the water heater worked. She was cold, she was hot, she was bored. Any pretext was enough for them to end up tangled together on the couch, in the kitchen, on the bathroom floor, with Lucía opening herself to him in increasingly obscene ways, making him eat her from the front, from behind, against the wall, while she begged him to fill her and leave her dripping for hours.

***

She took the next step. One afternoon she led him by the hand to the bedroom Damián shared with Carolina and threw herself onto the double bed.

—Here —she said, patting the mattress—. My sister sleeps on this side, right?

—Lucía…

—Fuck me while you think about her. Imagine she’s watching.

He should have said no. Instead, he climbed on top of her. And it was worse, because the idea set him on fire: the betrayal on those very sheets, his wife’s perfume on the pillow while he buried himself in her sister. He took her slowly, savoring every inch, until the rhythm became impossible to contain. Lucía grabbed the headboard, spread her legs wider, and begged him to fill her harder, to make her moan beneath the roof where Carolina slept. Damián gave her exactly that: long, deep, brutal thrusts, the bed banging against the wall while she came with her thighs trembling and her neck red from moaning so much.

That afternoon Lucía wanted more. She got on all fours, looked over her shoulder, and asked him, with a mixture of embarrassment and desire, to try her from behind. Damián prepared her patiently, with saliva and his fingers, attentive to every one of her reactions, sinking in one finger first, then two, opening her slowly until her anus stopped closing around the pressure and began to accept him. When she finally took him whole, Lucía buried her face in the pillow and asked him not to stop for anything. He gripped her waist and began to fuck her hard, driving into her from behind with dry, jolting thrusts that shook her whole body, while one hand dropped between her legs again to keep touching her until she lost her mind all over again.

They collapsed, breathless, onto the unmade bed. Damián tidied everything afterward with almost ridiculous care, smoothing the sheets, turning over the pillow, erasing every trace like a meticulous thief.

***

The risk became part of the game. At Sunday dinners, when Carolina cooked for the three of them, Lucía ran her foot up Damián’s leg beneath the table, moving slowly, looking him in the eye while she chatted with her sister about anything at all. Damián learned to hold his wife’s gaze without a muscle moving in his face.

Until they were almost caught.

One afternoon Carolina came home early from the bank with a headache. They heard her come in while they were on the couch, Lucía sitting on top of him. They had ten seconds to get dressed, disheveled and hearts pounding, pretending to watch television when Carolina crossed the living room.

—It’s so hot —she said, suspecting nothing as she set her purse on the table.

That night, while he was with his wife, Damián closed his eyes and thought of Lucía. He hated himself for it. And yet it was the most intense sex he had had with Carolina in months.

***

The arrangement ended when Lucía’s parents returned from the cruise and she moved back in with them. Damián thought that was where it would end, that distance and common sense would do the work he had been unable to do.

He was wrong.

Lucía began showing up with any excuse. She had come to pick up something she’d forgotten. She was stopping by to say hello. She wanted to see her sister, and stayed until Carolina went grocery shopping. Every visit found its stolen minute: the bathroom during a family dinner, the car parked in the garage, an empty room in her parents’ house while the table filled with people on the other side of the door.

—You know what the worst part is? —she told him one of those afternoons, still breathless as she adjusted her clothes—. I don’t regret a thing.

Neither did Damián. He knew it was a disaster waiting to explode, that sooner or later someone would put the pieces together, that he was gambling with the only stable thing he had. He knew it every time, and every time he came back.

Because in the end, he realized, it had all started with a silly lie one summer afternoon. A made-up itch, an excuse neither of them believed. And after that, there was no way to scratch the desire without seeking each other out again.