Work Text:
It was late, or some approximation of it, at least. Late, on a fugitive spaceship floating through an unnamed solar system, was more of a concept, than a concrete time, but, presently, that concept was in full swing. Every Stellaron Hunter aboard had gone to their rooms, and, while most likely weren’t asleep yet, more than a few were certainly headed that way.
Firefly was one of those. She had brushed her teeth, and was in her pajamas, curled up beneath the sheets with the lights turned off, trying her hardest to let sleep take her. It was cold in her room, though—in the whole ship, really—and, truth be told, she wasn’t all that tired just yet. She normally had a fairly early bedtime, but, tonight, the sleepiness hadn’t quite begun to set in yet.
At first, she was determined to simply stare at the unlit ceiling until it did, but, after a while, boredom trumped willpower, and she crawled out of bed. She stepped into her slippers, and, as quietly as she could, opened her door, and made her way into the hall. She crept through the dimly lit corridor, only aided by the flickering safety lights, and, after passing by a handful of rooms, she stopped. She stopped right in front of someone else’s door, and, before she could reconsider, she knocked.
Knock. Knock.
“Stelle?” She called out, hoping the girl would still be awake.
Stelle usually kept her door unlocked during the night, but, even so, Firefly didn’t want to just barge in. That would be rude. Thankfully, after a moment, the door slid open, and Stelle stood behind it, wearing an oversized shirt with the sleeves cut off, and a loose pair of boxers.
“Firefly?” Stelle ran a hand through her hair, eyes half lidded. She was clearly tired.
“Oh, were you asleep?” Firefly shifted from one foot to the other, feeling a little guilty for waking her up. “I didn’t think you would be yet, sorry.”
Stelle clearly didn’t mind, though, a smile plastered across her face. “It’s okay. What’s up?”
Firefly’s gaze shifted down, before realizing it looked like she was staring at Stelle’s bulge, and she quickly looked back up. “I can’t sleep.”
“Aww,” and Stelle’s lips turned into a frown. “I’m sorry.”
“Do you mind if I sleep with you tonight?” Firefly said it so bashfully, but all it did was make Stelle grin. She couldn’t have been happier about it.
“Of course you can. Come here.” When Firefly stepped into Stelle’s room, Stelle shut the door behind her, arm hooking around her waist. “You can always come and sleep with your big sis.”
Firefly could feel her face warming ever so slightly, turning pink. “Thank you. It’s always so much warmer in your room.”
Stelle simply shrugged. “Perks of being closer to the engine, I guess.” Then, she sat down on her bed, pulling Firefly closer, making her stand in front of her. “You brushed your teeth already?”
“Mhm,” and Firefly nodded.
Stelle pulled her down into the bed, inching her way closer to the wall, so Firefly had room to lay down. “Good girl.”
Firefly huddled up close to her, laying on her side, head tucked against Stelle’s chest, and Stelle simply slung an arm over her, pulling the comforter over the two of them. She had to admit, this was much nicer than sleeping alone. Stelle’s room might’ve been warmer, but the girl herself radiated warmth, as well, body heat seeping into Firefly’s bones, making her feel like jelly.
She was content, then, even if she wasn’t going to sleep yet. She was happy to simply lay with Stelle, to be cuddled up next to her, with her arm over her waist, listening to the beat of her heart, and the rise and fall of her chest. It made her smile, made her chest sing, and set her at ease like nothing else could.
Eventually, though, the hand Stelle had on her waist drifted downward slightly, and, though Firefly couldn’t tell whether or not it was intentional, Stelle’s hand landed on her ass, and squeezed. She did her very best not to make a sound, but, nevertheless, it made her heart start racing, pounding away in her chest. How could it not? How could she stop herself from trembling, from whimpering, as Stelle groped her over her pajama bottoms, from trying to grind against her, desperate for friction?
“Firefly,” and Stelle’s voice was low, and teasing, drawing out the name like she had just caught her doing something bad. She most certainly wasn’t asleep. “Are you thinking naughty thoughts?”
“No.” Firefly’s answer almost came out as a whine, gaze drifting up to find Stelle staring right down at her.
“Is that the truth?” and Stelle simply smirked, breathing in deep the scent of Firefly's hair. “Are you sure you didn’t come here just to fantasize about your older sister?”
“I didn’t.” Firefly pouted; she was telling the truth, really. “I was just cold, and I couldn’t sleep.”
“Mm.” Stelle hummed, using two fingers to tilt Firefly’s chin upwards. “Well now I can’t sleep either, not while my cute little sister is lying right next to me.”
Stelle kissed her, then, leaning down, and pressing their lips together, while her hand once more squeezed at Firefly’s ass. Firefly whimpered into it, leaning up as far as she could, already spreading her mouth open, and letting Stelle’s tongue find her own. It made her lightheaded. It made the whole world spin beneath her eyelids, and it didn’t help when Stelle grabbed one of her thighs, and pulled Firefly on top of her.
“You’re so naughty, sis.” Stelle spoke between kisses, pulling away only slightly. “I don’t mind, though. We don’t have to tell mom.”
Stelle’s hands were on Firefly’s hips, her thumb playing at the waistband of her cotton pajama pants, and, like that, all Firefly could do was grind against Stelle’s stomach, doing her best to stay balanced. “Stelle.” She cried, and one of Stelle’s hands slid up the back of her shirt, making her gasp. “Your hand is so cold.”
“We’ll have to warm each other up, then.” With that, Stelle sat up, sliding back, and leaning against the headboard.
Firefly let out a shaky breath, watching, as Stelle slowly undid the buttons of her pajama top. First one, and then two, and three, and four—it didn’t take long for her shirt to be fully opened, exposing her bare skin to the air of Stelle’s room, to Stelle’s eyes. She could barely breathe when Stelle slid her hands up her sides, fingers counting her ribs, thumbs playing with the idea of fondling her chest.
“You’re so cute, Firefly,” and Stelle leaned closer, head ducking down, so she could trail kisses down Firefly’s neck. Down, and down she went, until she made it all the way to the girl’s breasts, kissing right at her soft, pink nipple.
“Ah- Stelle.” Firefly moaned her name, biting her lip, trying to be quiet.
Stelle let her teeth nip at the bud, and it made the girl’s whole body tense, back arching into it. “Better not be too loud.” Stelle whispered, as she worked her way back up, using her hands to fully remove Firefly’s pajama top. “You don’t want mom to hear, right? Her room’s right across from mine, you know?”
Firefly threaded her hands through Stelle’s hair, hips rocking against her ever so slightly. “I can stay quiet, big sis; I promise.”
“Good girl,” and Stelle sucked a mark right beneath the line of her jaw. “Can you sit back for me?”
Firefly did as she was asked, letting her legs straighten out, and Stelle wasted no time in pulling off the girl’s soft pajama pants. When she did, though, Firefly huddled even closer to her, bodies pressing together all over. “I’m cold.”
“Aww, it’s okay.” Stelle reached past Firefly, and pulled a blanket over her shoulders, guiding the girl to sit back some.
That made Firefly pout, though, staring down at Stelle. “How come you still get to have a shirt on?”
“Oh? Is that ‘not fair?’” Stelle teased, exaggeratedly mocking Firefly’s tone of voice.
Firefly, however, simply started pulling at the hem of Stelle’s shirt. “It’s not.” She complained, drawing out the word until Stelle finally pulled her shirt off. With Stelle now shirtless, Firefly couldn’t help but stare.
It made Stelle smirk. “Do you like your big sister’s tits, Firefly?”
Firefly could only nod, gaze fixed on Stelle’s breasts.
Then, Stelle gently grabbed one of Firefly’s wrists, guiding the girl’s hand to her chest, and, when Firefly gave a tentative squeeze, Stelle let out a very clearly exaggerated moan.
This time, it was Firefly that kissed Stelle, leaning back in, and pressing their lips together, as she pawed at Stelle’s chest. Stelle smiled into it, but she didn’t let go of Firefly’s wrist, not even as her other hand once again groped at her ass, fingers dipping just beneath the line of her panties. It made Firefly squirm in her lap, sighing into the kiss, head feeling light, and fuzzy.
When Stelle dragged Firefly’s hand away from her chest, though, Firefly’s breath nearly gave out. Stelle guided her hand down, and down, down her toned stomach, past the waistband of her boxers, and to her bulge, dick already growing hard beneath her underwear. It made Firefly gasp, as Stelle pushed her hand up, and down the cloth covered length of her shaft, able to feel every vein, every twitch.
When Stelle finally broke the kiss, she was breathing considerably harder. “Do you like my cock just as much?”
Firefly simply nodded, mouth slightly agape. “Yeah.”
“Can you pull it out for me?” Stelle said it like a whisper, and it sent shivers down Firefly’s spine.
Firefly always found it easy to do what her sister asked. Slowly, she let her fingers slide between the opening at the crotch of Stelle’s boxers, spreading the fabric apart, and she slipped her cock through it, letting it press upward against Stelle’s own stomach. Gently, Firefly let her thumb roll over the tip, precum wetting her fingers, and she slowly stroked up, and down, making Stelle bite her lip.
“Fuck, your hand feels so good, little sis.” She said it like an exhale, hot, and breathy against Firefly’s ear. “Anytime I get off, I always wish it was you doing it instead.”
That made Firefly shrink into herself, though, shaking slightly, hand pressing down at the base of Stelle’s shaft.
“Do you ever think about me, Firefly? When you rub your clit?”
Firefly started stroking faster, and faster, then, and it made Stelle groan. “Yeah. All the time. It’s always you, or- Or mom, or Wolfie.”
Stelle was having a hard time thinking, speaking, not letting her hips buck up into Firefly’s hand. If she were a weaker woman, she’d probably be close already. “Is it- Mm- Is it ever all three of us?”
Firefly didn’t answer that one, but her thoughts were apparent with the way her hand stilled, and her teeth chewed at her lip.
It made Stelle smirk, and she pressed a kiss to the soft spot just behind Firefly’s ear. When she let her hand find Firefly’s panties, though, palming at her cunt, Firefly moaned. “You’re so wet.”
“S- Stelle.” Already, her hips were rocking against Stelle’s hand.
Stelle pulled down Firefly’s underwear, letting her clit, and her balls fall out, before smiling, and she pressed her thumb just beneath the tip. “Your pussy is so pretty, little sis.”
The only thing Firefly could think of at that moment was the way Stelle’s thumb drew slow, firm circles against the tip of her clit. It made her want to cry. “Th- Thank you.”
“Come here,” and Stelle put a hand on Firefly’s ass, pulling her as close as she could get. Before doing anything else, though, she held her hand up to Firefly’s face. “Spit.”
Firefly took a moment to gather as much saliva in her mouth as she could, before eventually spitting directly into Stelle’s hand, holding her gaze while she did.
“Good girl.”
Using the hand Firefly spit in, she wrapped it around the both of them, pressing her cock against Firefly’s clit, using the spit to ease the motion of her hand. She stroked slowly, at first—up, and down, long, drawn out motions of her hand, so that she could relish in the way Firefly bucked, and whimpered. They were so close, like that, pressed together almost everywhere, and, when Stelle pressed their lips together as well, she could practically taste the delicious moans that fell from Firefly’s mouth.
She didn’t stay slow forever, though. Her hand sped up; her hips bucked. She was larger than Firefly by at least an inch or two, and the way the girl’s clit dragged against her cock made it so very hard for Stelle to breathe. It felt perfect, aided by precum, by slick, all wet, and warm, and each little twitch of Firefly’s hips, easy spasm of her arms, or whimper against Stelle’s shoulder only made it feel better.
“B- Big sis, I-” Whatever Firefly was trying to say was cut off by a moan, open mouthed, and wet against Stelle’s skin.
It made Stelle smile. “Does that feel good, Firefly?”
Firefly could only nod desperately.
“Do you wanna feel even better?”
Firefly bit her lip, leaning back up, holding Stelle’s gaze. “How?”
“Like this,” and, as Stelle kissed Firefly, her hand stilled, and she pulled it away.
It made Firefly whine, at first, but, when they broke apart, and Stelle licked her hand clean of their fluids, complaining was the last thing on her mind.
Then, Stelle leaned to the side, sliding open the drawer on her nightstand, and clumsily fumbling through it, trying to find the lube she kept within. Once it was procured, she sat back up straight, rolling the bottle in her hands for a moment, before speaking.
“You know I love you, right?”
Firefly simply nodded. “Yeah.”
Stelle leaned in closer to her, kissing a line up Firefly’s neck, all the way to her ear, and, when she spoke, it came out like a whisper, low, and gravely. “Is it okay if big sis doesn’t use a condom this time?”
“I-” Firefly bit her lip, gaze drifting downwards in embarrassment. “I don’t know.”
“I wanna cum in you so bad, Firefly. Don’t you wanna feel your big sister fill you up like that?”
It sent a chill down Firefly’s spine, and the way she trembled in Stelle’s lap made her grin.
“We don’t have to tell anyone—not mom, not Wolfie. It can be our little secret, just you and me.”
Firefly was breathing so very heavily, heart pounding in her chest, as goosebumps formed on the back of her neck. “Okay.” She swallowed, hard. “Yeah. That’s okay.”
“Good girl,” and Stelle took the opportunity to kiss down the center of Firefly’s chest, lips pressing against the insides of her breasts. “I love you so much, little sis.”
“Ah- Stelle.” Firefly arched into it, back rolling forward, while her hands held Stelle’s shoulders for support.
Then, Stelle’s thumbs dragged down Firefly’s panties, pulling at the waistband until she couldn’t anymore. “Can you take these off for me?”
Firefly did as she was asked, shimmying awkwardly in Stelle’s lap in order to remove her last scrap of clothing, and, while she did, Stelle took the opportunity to pull down her boxers, kicking them off the side of the bed. When Firefly finally settled once more, now fully naked, sitting on top of Stelle’s thighs, Stelle couldn’t help but run her hands over her things, tracing downwards, past her pussy, all the way to her asshole.
It made Firefly lurch forward, legs spreading unconsciously to give Stelle easier access. “Don’t tease me.” She pouted.
Stelle could only grin, pressing a kiss to the girl’s temple. “Don’t worry.” She said, and she uncapped the lube, squeezing some onto her fingers.
She pressed inside of Firefly ever so slowly, fanning her fingers apart, gingerly pumping her wrist, getting her ready. It made Firefly whimper, and bite her lip, and it felt almost impossible for her to stay still. Firefly rocked down against Stelle’s fingers, knowing they weren’t supposed to be the main attraction, but, fuck, it just felt too good not to. When Stelle finally pulled her fingers back out, though, it made Firefly want to cry.
“Shh,” and Stelle pressed kisses to Firefly’s face, meanwhile squeezing more lube into her hand, and working it up, and down her shaft. “I know you’ll take me so well; you always do.”
“Hurry up,” was the only thing Firefly could say.
Stelle put a hand on Firefly’s ass, spreading her open, and she used the other to line herself up, to press the head of her cock against Firefly’s asshole. “You’re lucky I’m not mom. She’d have made you say please, but me?” She lifted her hips upward, sliding just the tip inside. “I don’t mind when you get a little impatient.”
It made Firefly groan, especially as Stelle pulled her down on top of her, pressing inside further, and further. Inch by inch, Firefly squirmed, as Stelle worked her way inside, and, when her ass finally met Stelle’s hips, she swore she could feel it in her throat. Fuck, Stelle was just so big—so much bigger than her, or Silver Wolf, or even most of the straps that Kafka liked to use. It was so much. She hit her in her very deepest spots, carving out a space for herself until it felt like Firefly had been perfectly molded to her.
It didn’t help, either, when Stelle started rocking up into her, sliding down, pulling out, and then thrusting back in as deep as she could go. All Firefly could do was hold on, hips bucking somewhat, sure, but face buried in the crook of Stelle’s neck, arms desperately wrapped around her shoulders. She could tell she was leaking, precum dripping down her, and onto Stelle’s stomach, more coming out with each, and every thrust inside her. It made her lightheaded; it made her want to cry.
“Big sis.” It came out like a moan, high pitched, and louder than she had meant it to be. “I feel so full.”
“You’re- Ah- You’re doing perfect. You feel so good, Firefly.” Stelle’s words were broken up with groans, and sharp inhales, each sound making Firefly’s head spin.
Firefly couldn’t stop her hips from rocking, then, using her legs to lift up, and drop back down on Stelle’s cock, fucking herself in time with each of Stelle’s thrusts. It only made it better when Stelle slid a hand down to the base of her spine, rubbing slow circles, relaxing her, making it easier to take more, faster. Faster was exactly what Stelle became, too. Her hips moved faster, fucking into Firefly harder, and deeper, grinding in whenever she bottomed out, and spreading the girl open whenever she pulled back.
Like that, Firefly simply couldn’t stay quiet. Her voice bobbed with Stelle’s thrusts, moans, and whines pouring from her throat directly into Stelle’s ear, bouncing off the walls, as the bed creaked, and groaned with their combined efforts. She cursed, and begged for more, and desperately held onto Stelle for balance, and Stelle gave her everything she wanted, and more.
“Stelle- Stelle-” Firefly pleaded desperately, unable to quite get the words out.
She couldn’t stop the impending crescendo from ricocheting through her, though. From the tips of her fingers, to the small of her back, every nerve sang out simultaneously, a beautiful symphony thrumming through her bloodstream, as her mouth hung open in quiet, stilted pleasure. Cum dribbled out of her, and onto Stelle’s stomach, and her asshole clenched so very tightly. She was sure Stelle knew, confident that she could tell, but, fuck, she didn’t have it in her to say a single word at that point.
Stelle, for her part, rode Firefly through it as best as she could. She stayed buried inside, digging her hips in, forcing out every single drop of cum that she could, and, when Firefly’s jaw snapped shut once more, she kissed her, wanting to taste the euphoria on her lips. She groped at Firefly’s ass, and whispered sweet nothings directly into her ear, letting the girl rock against her as much as she pleased.
Eventually, though, she stopped, slumping forward against Stelle, and it made Stelle grin. She was going to say something cheeky, something to tease Firefly, to rile her back up, but the look in her eyes when Firefly looked up at her made her stop. She just looked so pure, almost innocent, lips slightly spread open, eyes watering. She seemed desperate, and content at the same time, and, despite how hard Stelle always tried to control herself around the girl, this time she found it impossible to.
Without warning Firefly, Stelle grabbed her by the waist, and lifted her into the air, slamming her down onto her back, and making her legs fly into the air. One of those legs ended up pinned beneath Stelle, while the other got lifted up, and over her shoulder, Stelle looming over, while Firefly laid on her side, unable to do anything other than wait with bated breath.
“Big sis…” Firefly trailed off, the air clearly having been knocked out of her when Stelle pressed her to her back.
Stelle couldn’t wait anymore, then. Wrapping an arm around Firefly’s thigh, she slid back in, this time hard, and fast, slamming inside as deep as she could. It made Firefly squirm underneath her, moaning, one hand gripping the sheets, while the other was tossed behind Stelle’s neck. She fucked fast, and shallow, barely pulling out before she was thrusting back in, pounding against Firefly’s deepest spots over, and over again.
It made Firefly throw her head back, eyes squeezing shut, and moaning. “B- Big sis- Fuck. Harder, please.”
Stelle wasn’t ever one to ignore a request like that. She fucked deep into Firefly as hard as she could, pulling out further, putting more, and more force behind her hips. “You’re so-” She was cut off, a sharp inhale drawn through clenched teeth, as Firefly dug her nails into Stelle’s back. “Such a good little sister. Taking me so well.” She could barely get the words out.
After that, it was a blur, bodies moving together, animalistic, and harsh. Stelle fucked Firefly as hard as she could, fast, deep strokes making the girl squirm, and writhe beneath her. Firefly could only moan, and take it all, voice growing louder with each thrust, nails digging into Stelle’s skin. It just felt too good; it made tears form in Firefly’s eyes, made her legs burn, made it hard to breathe.
Stelle was much the same. Her breathing was ragged, hips aching from the exertion, but she felt much too good to stop now. She rutted desperately into Firefly, fucking her little sister with all the force she could manage. She could tell her pace was stumbling, could tell she was losing some of her strength, her rhythm, but, even still, she was relentless, refusing to pause for even a second.
That task was almost impossible, though, when she leaned down, pressing Firefly’s leg against her stomach, and the girl whispered directly into her ear.
“Big sis.” It was said like a whine, or a whimper, high pitched, needy, and brainless. “Big sis, can you cum in me? Please? I want it so bad.”
Stelle’s breath caught in her throat, heart beating so fast she could almost taste it. “You- Ah-” Anytime she tried to speak, it came out as a groan. “You’re sure? You’re not gonna- fuck- run and tell mom, right? You know we’ll get in trouble.”
“I won’t; I promise.” Tears were streaming down Firefly’s cheeks, as she shook her head. “I need it. I need you to fill me with it.”
Stelle grinned, letting Firefly’s leg fall away, and tucking her face in the crook of the girl’s neck. “Such a naughty little sister, Firefly, but,” She paused, nipping at her jaw, and, already, she could feel her cock pulsing with each spurt of cum, “if that’s what you want.”
It was so intense, like that. Stelle dug her hips in as deep as she could, letting cum pour out of her, and into Firefly’s ass. She came so much, too—much more than usual, as if the idea of cumming raw inside her little sister kicked her into overdrive. She groaned, as she came, open mouthed, warm, and wet against Firefly’s neck, and it took all the willpower she could muster not to sink her teeth into the pearly flesh, not to bite, and rip, and tear.
Firefly’s eyes widened, as she felt Stelle pulse inside of her. She wasn’t sure if she had cum again, but, even if she had, she couldn’t tell. She didn’t really care either way, though. Having Stelle like that, feeling her insides get filled with her big sister’s cum—that was more than enough for her. She did everything she could to draw out as much as possible, too, clenching her ass, rocking down into Stelle, running a hand through her hair. Fuck, it was perfect.
When Stelle finally pulled out of her, Firefly could feel cum trickling out of her ass. It made her squirm, but Stelle simply rolled her to her back, kissing her, quieting her.
“Shh, it’s okay,” and she put a hand on the bottom of Firefly’s stomach. “Can you feel it?”
Firefly nodded, head fuzzy, and full with bliss. “It’s so warm.”
It didn’t feel much different than usual, truth be told—not really. She could feel it shift when she moved, though, could feel it dripping out of her ass and down onto the sheets. The knowledge that she was filled with Stelle’s cum, that it didn’t get pulled out of her, tied off, and thrown away, was where most of the satisfaction came from. It felt special. It felt like a secret made just for the two of them, just like Stelle had said.
Stelle kissed her all over her face, hands cupping her jaw. “You’re such a good girl, Firefly. The very best little sister I could’ve asked for.”
That made her hum with delight, grinning ear to ear, practically melting into the sheets. “I’m sleepy, big sis.”
“Let’s get cleaned up, and then we can go to bed, okay?”
Firefly nodded. What she didn’t do, though, was move, instead choosing to lay still, body still awash in bliss. It was Stelle that had to drag her to her wobbly, unsure feet, and hold her steady, as they took care of themselves.