a/n: i have already warned you in the disclaimer that this is incest, clearly an au brought to you by the wonderful tumblr and the blainchel fandom over there that wouldn't leave me alone until i wrote this. i don't know how that translated into 5,000 words of angst and smut, but you've been warned. don't judge me.
Blaine couldn't remember a time when Rachel hadn't been the most attractive girl in a room, when he didn't want to move heaven and hell for her if she dared to ask, when he wouldn't have given anything to call her his own. He had loved her his whole life-or frankly her whole life-she was, after all, a year younger than him. It was only as they grew older that his interest changed, grew, the short skirts she started wearing causing him to do double-takes, the tight tanks and short shorts she'd wear as pajamas late at night causing him discomfort, because he wasn't supposed to have these thoughts. He wasn't supposed to be lusting after her, wanting nothing more than to pin her against a wall or slip into her bed late at night.
He wasn't supposed to want her like he did, and he hated himself every single time one of those thoughts would run through his mind, unable to stop it from implanting and taking fruition as he watched her flirt with her boyfriend at the kitchen table, crossing her long legs before sliding them underneath her as she leaned over to correct something on Finn's paper in front of him.
He was supposed to be her brother, and this was not supposed to send him into some sort of hazy tailspin of desire.
"Blaine Anderson-Berry!" Rachel yelled from across the hall, his head snapping up quickly to see her storm into his room, wiling himself to keep his eyes on her face.
"What?" he asked, trying to focus his attention back on his AP English assignment as she huffed from the doorway, hair tossed up in a messy bun as it usually was once she had showered for the evening, gold star boxer shorts he had gotten for her for Christmas last year barely covering anything.
"Don't what me," she snapped, now moving closer to him. He had to fight to keep his eyes down now, using all his strength not to grab her by the waist and lift her on his desk, to devour her mouth with his own, and he knew when she left, he was going to have to take a very cold shower or risk her walking in as she tended to do without thinking. "You stole my microphone again, and I need it to record a song that I think we're going to use for Regionals!"
Blaine couldn't hide the smirk that grew on his face. He had hidden it-deep in the cabinets in their basement where their parents kept files on the two of them, from their birth records to any and all school certificates. Rachel had told an ex-boyfriend (one that Blaine really disliked) that it was practically a shrine to them, a little Rachel and Blaine museum in the making. 'When I'm famous,' he had overheard her confiding in the Jesse kid, 'they can open up the basement and people can pay to find out anything they want about me.'
"I may have taken it away from you," he said nonchalantly, turning a page in his book, ignoring her huff of annoyance.
"I need it!" she practically screeched, and he just rolled his eyes, turning to face her.
"And I need to sleep at some point," he retorted. "Which I can't do if you're constantly singing." She pouted, looking a little hurt, but he tried to ignore it, ignore the weird throb of pain he got whenever she looked sad, knowing she was doing it just to get a reaction from him.
"Just tell me where it is?" she pleaded, her eyes opening exceptionally wide as she looked at him, the picture of innocence as she moved towards him, a hand gently resting on his chest as she looked up at him. He took a breath to steady himself, not giving in to the game she was clearly playing.
"No," he said, though his voice was wavering the closer she stood to him, and he wanted to yell at her that she was his little sister, his baby sister, and she shouldn't stand that close when she was barely dressed, her tank ridden up a little. He had to focus his gaze on the ceiling and think about literally anything other than the way her hand felt even through the fabric of his shirt.
"Please?" she asked, her voice quiet, and he was so close to giving in and giving her anything she wanted, so long as she stopped touching him, stopped being near him, left him alone so he could hide in his shame.
"Rachel," he said instead, his voice a warning-though a warning for what, he wasn't sure, because as much as he wanted her to go away and leave him be, there was a bigger part of him that wanted to lean down and kiss her, make her feel things he was sure that gigantic asshole of a boyfriend she had wasn't making her feel.
"Fine," she snapped, her hand immediately retracting itself and the fire back in her eyes as she glared. "But I swear to god Blaine, I will find it, and I will wait until you are asleep, and I will sing Mariah Carey's greatest hits at the top of my lungs as payback," she informed him angrily before storming out, a low sigh escaping his lips as he watched her go, already knowing every word she said was more than likely true.
His punishment for hiding her prized possession was almost far worse, leading her to ignore him for three days until he placed the bedazzled microphone back on her bed in a moment of weakness, the only contact he had had with her being a short 'hello' as she stomped past him early in the morning on her way to the shower after her workout two days prior.
"Thank you," she said quietly as she passed him in the hallway later that night, reaching out a hand to rest on his arm momentarily before heading back down towards the basement to practice for whatever Glee-related project she had going on for the week. Blaine stayed rooted in his place, staring at the spot she had touched as if it was going to do something interesting before realizing how foolish he looked before disappearing to hide away in his room, turning up loud, angry music to drown out the voices yelling at him in his head.
He thought, for the umpteenth time, that maybe a girlfriend would help him move on from this weird thing he felt towards her. But he had dated girls, dated cheerleaders and nerds, none of them leaving him as breathless as Rachel could just from a simple look. None of them made him feel anything; they were just used as a distraction, a normal, sane way to get off before he sent them on their way, never lasting longer than a month or two at the most.
She teased him often, joking that maybe his problem was that he secretly had eyes for boys instead-he spent an awful lot of time flirting with her friend Kurt, after all. But he simply rolled his eyes at her accusations, pushing her away from him when she got in those moods, smiling a bit as she'd giggle at him.
"If you could date anyone you wanted," she had asked one night, a couple summers ago before her sophomore year of high school, "whom would you date?"
He bit back the 'you' that he wanted to reply with, the honest answer, and instead rubbed his eyes and shrugged. "I don't know. Santana Lopez I guess," he answered, slightly annoyed at the laughter that erupted out of her as she rolled on his bed, processing the information. "Fine, what about you," he had asked, his tone harder than it normally was around Rachel.
She had shrugged, but he knew the answer before it even came out. "Finn Hudson, I suppose," she said, but he knew well enough that it wasn't an I suppose, it was a full grown crush, had watched the two interact around school as she tried to lure him away from Quinn Fabray. He knew she deserved better, someone who was far more talented than Finn-not that Finn wasn't talented, and at least he was in the New Directions. Blaine, despite Rachel's pleas, couldn't stand to be in the group, not if it meant watching the two of them making googly eyes at each other and sing duets together.
But that was over a year ago now, and Rachel had managed to not only secure her spot as Finn Hudson's girlfriend, but as Blaine was forced to endure the few times he stayed in the house when Finn was around, managed to lose her virginity to him too. They no longer talked about crushes and feelings, because he would tell her exactly what his opinion on Finn was, and she wouldn't like it.
So instead, he laid in his bed, the shame washing over him as he once more unbuttoned his jeans and got off to thoughts of his sister.
"How come I have to hear from Hudson that your family is going away for Christmas break?" Mike Chang complained as he walked up to Blaine's locker, Blaine shooting him a confused look.
"What the hell are you talking about?" he asked. "We're not going anywhere? I mean, I think my parents are-somewhere in Europe or the Caribbean again, I don't know I stopped paying attention."
"That's not what Hudson said," Mike said warily, and Blaine just responded with an eye roll. "He said that Rachel informed him you guys were all taking a family vacation so she couldn't see him during Christmas break, and he was going on and on about how he felt like getting her earrings was a waste if he wasn't even-" Mike paused, seeming to realize who he was talking too, but Blaine just shrugged.
"If he wasn't going to get laid?" he offered, and Mike just stuttered out a short apology before Blaine smirked. "You act like I don't sleep across the hall from her. It's not like I'm stupid."
"Still, she's your sister," Mike said, emphasizing the word 'sister' a little too much for Blaine's taste. "You don't want to hear about her sex life."
"I don't," Blaine agreed whole heartedly. "But I also want to know if Finn is being a douche so when I finally get around to punching him in the face, I can explain why to Rachel. She's kind of scary when she's mad."
"But why would she tell Hudson she can't see him over Christmas break if you're not going anywhere?" Mike said after a few moments, and Blaine couldn't do anything but shrug, his eyes drawn automatically to where the girl in question was chatting with Kurt, completely wrapped up in her own world that she didn't even notice Blaine's stare.
"Maybe she just doesn't like him anymore," Blaine supplied for an answer. "Not that I'd blame her. The two are horrible together. Besides, he's like 12 feet tall."
"You have some sort of inferiority complex against tall guys," Mike chuckled. "And he's not that bad. He's just, you know-"
"Fucking my sister?" Blaine retorted, trying to keep the bitter resentment out of his voice. He had no reason to hate Finn, not really. Sure he could be a bit of a dick, but he made Rachel happy, and he was allowed to date her. No one ever judged them walking down the halls together, hand in hand. No one thought their relationship was sick, wrong, perverted.
Not like they would if it was Blaine kissing her between classes, telling her how gorgeous she looked in her new sweater, tucking stray pieces of hair behind her ear.
Those things were reserved for Finn.
"How come you told Finn we were going away for Christmas break?" Blaine asked Rachel later that night, when it was just the two of them in the kitchen grabbing snacks before heading off to their separate rooms to finish studying for mid-terms.
"What?" she responded, nearly dropping her bottle of water in the process. He caught it before it hit the ground, a grin on his face as he handed it off to her.
"Apparently Hudson told Chang that buying you earrings for Christmas was useless if he couldn't cash in on it until we came back from vacation," Blaine told her frankly, watching her carefully as she blew the bangs out of her face.
"I don't think that's any of your business," she said haughtily, her tone sharp in a way that he hated to admit turned him on more than it should.
"Au contraire," he retorted. "I think it is. As your older brother-"
"That's all you are Blaine, my brother," she hissed, causing him to pause in his speech he was about to launch into, feeling like he had just gotten slapped in the face.
"I wasn't-Rach, I'm trying to look out for you," he finally stuttered out, worried she had noticed how fucked up his feelings towards her were, worried she had finally seen just how un-brotherly he looked at her.
"You don't have to look out for me," she informed him, her voice still low and harsh. "I'm a big girl Blaine, I can look out for myself."
"I didn't say you couldn't," he said weakly, but she was already gone, stomping off towards her room loudly. He hung his head in his hands, muttering to himself about how badly he had fucked things up for both of them.
Rachel went into one of her modes where she ignored Blaine for days on end, their parents finally taking notice on their first day of winter vacation as they got ready to leave the house.
"Watch over your sister," their mom said, kissing Rachel's hairline quickly before pulling Blaine in for a hug.
"Even if she is mad at you," their dad joked, now hugging Rachel as she rolled her eyes in disgust. "And no burning down the house."
"We'll try our best," Blaine said, forcing on his most chipper smile. "Have fun in-erm-"
"Switzerland," his mom answered for him with a slight chuckle. "Your dad has business there. You guys will be okay, right? If you need anything, call your grandparents."
"We'll be fine," Rachel assured them, though she looked a little sad-their parents leaving would mean they were on their own for the holidays, her favorite time of the year. "Be safe," she requested, and they nodded before heading out the door, a cab waiting to bring them to the airport and leaving Rachel and Blaine waving behind from the front door.
"Are you still ignoring me?" he asked after their parents had pulled away, looking down at her as he shut the door behind him.
"No," she shrugged. "It's a lot harder than it looks and if I'm avoiding Finn then I have to avoid Kurt too, then I probably shouldn't cut you out too." She gave him a small smile, squeezing his wrist before turning and heading for the stairs, Blaine unsure if he should be happy or sad at the thought.
Blaine spent the next two days decorating the living room for Rachel, knowing that even if she wanted to hide out in her bedroom she'd have to leave it at some point. He went out and with the help of Mike set up a tree in their living room, stringing lights as he played Christmas carol's and sang along quietly.
"What are you doing?" she questioned when she finally appeared on the stairs around 2am, sitting on them as she watched him decorate.
"Throwing a tea party," he replied sarcastically, shooting her a grin as he did so. "I saved the ornaments for you to do, I know that's your favorite part."
"Thanks," Rachel said quietly, resting her head against the railing as she watched him. He continued humming along to the Nat King Cole song now playing on the radio, his smile widening when Rachel joined in from her spot, her voice quiet and melodic in a way that always amazed him. He gave her shit for singing all the time, but the truth was he didn't think he could imagine a world where he didn't get to hear her every day. He knew, better than even she probably did, that her dreams of Broadway and super stardom were an eventuality, an inevitably.
He knew that one day, he'd be sitting in the front row of a sold out theater clapping louder than the rest of the audience combined.
"Come sing with me," he requested, holding out a hand for her. It took her a moment, but she eventually got off the stairs and walked towards him, holding his hand loosely as he spun her around the room, the two of them singing along to the radio. Their smiles grew and turned into laughter as she nearly tripped over a box of ornaments, Blaine's hand reaching out to catch her instantly, pulling her close to him for a hug.
"I love you," she promised, and Blaine hummed in appreciation of the sentiment. If this was all he could get, hugs and platonic moments of love and adoration from her, he was going to damn well enjoy it.
He woke her up on Christmas Eve with pancakes in bed, covered in red and green sprinkles and real maple syrup just like she loved. "For me?" she asked, popping open an eye when she smelled the delicious meal, sitting up quickly without seeming to think that maybe she should wear something besides a large teeshirt, which Blaine realized was one of his own.
The thought floored him, watching as she moved the tray he had brought so that they could both eat off of it, opening his mouth automatically as she prodded him to take a bite of the pancake. "These are delicious," she said as she hummed happily around the food, hair falling loosely around her face and making her look even more gorgeous than she normally did in her just-woken-up state.
"Well," Blaine said once he realized he should probably say something, not continue staring at her like some sort of creep, "it's Christmas Eve. And I always make you breakfast on Christmas Eve."
Rachel sniggered, taking a sip of her juice. "I have to say, these pancakes are a vast improvement from the oatmeal mush you used to make me when we were younger," she joked lightly.
"I seem to remember someone getting really upset that year I wasn't here and she didn't get her oatmeal," Blaine teased back, Rachel chuckling as she leaned into his side, her hair tickling his chin as he placed a small kiss on the top of her head.
It was in moments like these that Blaine realized he was way more screwed than he could have hoped. He wanted his sister on a physical level, yes, but he wanted her on the emotional and romantic level too. He was in love with her as a guy more than he loved her as a brother, and in the end it was only going to hurt him more, and potentially hurt her too.
Still, he pasted on his best big brother smile and squeezed her shoulder, getting off the bed quickly as he grabbed her empty plate and tray. "Christmas special marathon starts in approximately one hour Rachel Anderson-Berry," he stated, his tone airy and light even if his heart felt heavy. "You better not be late, I am not going to be pleased if I have to wait to start Rudolph."
"Alcohol?" he asked with a raised eyebrow when she walked into the living room and rejoined him on the floor, It's A Wonderful Life playing silently on the TV behind them as she handed him a glass.
"Not just any alcohol," she replied with a sly grin. "Champagne. From dad's office."
"So you're trying to get me killed then," he half-joked as she popped open the top, giggling as she poured them each a flute of the bubbly drink. "And why are we drinking again?"
"Because it's Christmas Eve, and it's snowing, and we're stuck alone in this house while our parents are off exploring the world without us again," she waved away. "Also because I've never tried champagne before."
"All good reasons," he teased, clinking his glass with hers in a toast. "Although if they figure out we stole the good stuff, I'm blaming you," he told her after a sip.
"I'll just play the innocent little sister card," she grinned mischievously, and he rolled his eyes.
"You would think you've played that enough by now," he grumbled, ducking slightly as she moved a hand out to swat him.
By the time an hour or so had passed, the TV now a blue screen as neither were in a state to operate electronics, Blaine wasn't sure how he had let his sister get him drunk, only that he definitely was.
"I hate you," he mumbled, laying down next to her beneath the tree, rolling on his side and trying to support his head on his hand before letting it fall against the floor next to her own.
"I love you too," she promised, her voice quiet as she turned on her own side, her brown eyes searching his in a way he wasn't entirely sure about. The room was dim, the Christmas tree the only real source of light above them, and the different colors seemed to reflect in her eyes as he watched them, mesmerized by their hypnotic stare.
"Rachel," he said, his voice quiet, but she simply reached a finger out and placed it on his lips, effectively shushing him. When her lips met his own, it was in the middle, both of them leaning in to kiss the other, the moment sloppy and drunk and sobering all at the same time. It was nothing like kissing anyone else he had ever made out with, and when one of her hands pulled him closer by the back of his head, he wasn't about to object.
They lay like that for awhile, kissing under the tree in a way he figured was vaguely romantic, but then she was nuzzling into his neck, her lips soft against the light stubble he had from not shaving that morning. "We're drunk," he said quietly, not necessarily wanting her to stop as her hand moved from his hairline to his arm, holding him tight against her.
"I don't care," she replied, her breath tickling his ear.
"I do," he scolded, standing up and trying to pull away from her only to have her follow him anyways. "Rachel, we can't-I'm your-"
"I know!" she yelled, and he winced a bit at the sudden loud noise. "I know that it's wrong and all the other stuff, but Blaine-I love you, and you're here, and I'm here, and I want this just as much as you do. Why won't you get that?"
"What are you talking about?" Blaine asked, fighting the urge to cave in on himself, to curl up in a ball on the floor and avoid this conversation forever. Because the words coming out of her mouth didn't matter, nothing besides the fact that she seemed to know mattered.
"I'm talking about us," she said, lowering her voice just slightly as she took a step towards him. "Let's be honest here, okay? If we weren't siblings, we would have been dating a long time ago."
"No," Blaine tried to argue, but she just smirked in his direction, growing ever closer even as he tried to back up, the back of his legs hitting the couch before he realized he was there, falling onto the seat as she crawled on top of him, not even stopping until their faces were mere inches apart.
"Blaine, we both want this," she whispered, and he tried to deny it, tried to tell her she was being ridiculous, crazy, drunk, but then her cheek was ghosting along his as her teeth grasped onto his ear, causing his breath to hitch slightly. "Whether we were sober or not, I think this would be happening."
"Rachel," he said, trying to clear his mind, but she just shushed him with her lips on his again, her hands moving to grab his own and place them at her waist, whispering the word 'please' without parting their mouths.
Blaine was never one to deny such a simple request.
His hands tightened around her waist, her own falling to his chest as she unbuttoned his shirt, her mouth now back to trailing kisses from his lips to his chin to his shoulder, never staying in one spot any too long. He let his own hands trail up the sides of her shirt, lifting it as he went and smirking a bit when she sighed to back off and let him whip it over her head entirely, her hands never ceasing their descent towards his pants.
She snapped the button on his jeans, a sly grin on her face as she told him to lift his hips. He did so immediately, already half-hard as she slid his pants and boxers down, Blaine kicking them off in an effort to move things along quicker.
He let out a small gasp as she settled back on his lap, her hand finally reached it's destination. He couldn't help the groan that fell when he looked between them, actually witnessing her fingers wrapped around his dick. It was an image he had thought of for so long, but the reality was even better. It didn't take long for her hand to get him completely erect, his own hands cupping her face as he brought her mouth to his own. The kiss was sloppy and messy, both of them distracted by the events between them, but when he let out a low "Rachel," he felt her shudder on top of him and had to bite her lip to keep from doing so himself.
He tried to slip his hand into her sweats, but she just swatted it away with a glare and a quiet "Not yet," vacating his lap as he let out a whimper, missing the contact of her on top of him within seconds. But then she was situating herself between his legs, licking her lips in a way he was sure had to be illegal, and he knew he couldn't complain for long.
She hovered for a moment, her breath teasing more than her eyes locked on his own ever would, but when she finally slipped her mouth over the tip, he didn't even try and let out the long moan he let out. As her mouth moved lower, and lower-taking in far more of him than any girl he'd ever known could-he was convinced he was going to come in her mouth before he could even stop himself.
"Rachel," he said shakily, his head fallen back as his hands wound in her hair, letting out a shudder as she hummed in response around him. "Jesus fuck," he whispered, finally looking down at her. She was moving one hand along his dick with her mouth, the other disappeared into her own pants, and he had to quickly grab her face to get her to stop or it'd be a few minutes before he could do anything again. "Come here," he growled, and she complied immediately, slipping out of her own clothes quickly before resettling on his lap, her hand quickly back to playing with herself. He nipped at her chin, her shoulder, her breast before he moved her fingers to replace them with his own. They slid into her with ease, and the soft gasp she let out only pushed him further, moving his fingers quicker in and out before she was panting, begging for more.
"Please Blaine," she whined, her mouth pressed against his shoulder. "Please." He nodded, barely able to think of anything besides her body, her skin, his hands now trailing along the soft curves he had spent years of dreaming about, his teeth gently pulling on a nipple before sucking it greedily into his mouth as she let out more pleas.
"Positive?" He asked, reaching once more between them to align himself against her, waiting for her 'oh god, please Blaine,' before pushing in, both of them pausing for a moment at the new sensation.
You are inside your sister, a voice inside his head taunted, and it was such a wrong thought, something that should have made him pull out, but instead it only seemed to spur him on, his hips moving before he even consciously thought to.
She wrapped her arms around him, her breath uneven as her own hips moved for more, guiding his hand between them to gently play with her clit. She lay plain kisses on his torso, a moan or explicative falling against his skin every time he'd hit a good spot inside her, or his thumb pressed especially hard against her. He could barely focus on anything that wasn't the feel of being inside her, how tight and warm and wet it was, how perfect it was. Like he was made to be inside of her.
It was that thought that had him tumble over the edge, repeating her name over and over as he kissed her as hard as he could, thumb and finger pinching against her clit so that she would fall with him, both breathless as they held each other tightly.
"I love you," she finally whispered once he had pulled out of her, their bodies sweaty and sticky and completely entwined in one another's.
"I love you too," he promised, laying a quick kiss on her hairline, neither bothering to move as they lay on the couch, eyes in a hazy focus towards the Christmas tree still glowing in the corner. "Merry Christmas," he whispered, feeling her grin against his chest where she had curled up, feeling more than hearing the words repeated back to him.
When they awoke again in the morning, curled up tightly under a blanket Blaine had pulled over them at some point in the night, not a single word was mentioned, just a simple, soft kiss shared between the two in their cocoon, knowing that in the outside world it was wrong, and forbidden, and it would never be accepted. But there, in the dim morning sun, nothing mattered to them except each other and how each felt.