Title: Magic on Your Tongue
Author: gracerene
Characters/Pairings: Lily Luna Potter/James Sirius Potter, vague mentions of past Lily Luna Potter/OMCs
Rating: NC-17
Kinks/Themes Chosen: Breasts & Illegal Sex
Other Warnings/Content: sibling incest, underage in some countries (though not technically in the UK), oral sex, cunnilingus
Word Count: ~3,800
Summary/Description: "I can't stop thinking about it," Lily confesses, soft and urgent. "Nobody's ever made me feel so good, James. I want to feel like that again."
Author's Notes: Lily is 16 years old and James is 19. Sibling incest in the UK is a bit of a murky grey area, legality-wise, particularly when it's consensual and the participants are both over the legal age of consent (16), but I figure it's enough of a taboo to qualify to the Illegal Sex theme.
I envision this taking place in my Magic universe, but this can be read as a stand-alone fic, and you don't have to be familiar with the others to read this one.

All the thanks in the world to the amazing capitu for looking this over for me, and to the ever-brilliant lq_traintracks for her stellar beta work! She always has the best feedback! <3

Lily's heart races as she looks herself over in the mirror. She's wearing an oversized white cotton nightie, nothing special, but she knows the way the neck gapes open, revealing her slim shoulders and prominent collarbones, has its own kind of allure. The bottom falls to mid-thigh, showing off her long legs, artificially tanned with the fancy bronzing potion her best friend, Juliana, gave her for Christmas. Lily knows she looks good—her long red hair falling in graceful waves down her back, her perky breasts and hard nipples visible beneath the worn fabric of her nightie—but her stomach still cramps with nerves as she steals herself for the next part of her plan. Looks alone aren't enough, but Lily reminds herself of the prize and straightens her shoulders. It's the last night of Christmas hols, her last night at home before she has to return to Hogwarts, and Lily doesn't plan on leaving until she's finally experienced what was promised.

Sure, maybe James didn't directly promise it, not in so many words, but he was the one who put the idea in her head in the first place, the one who made the thought of his mouth on her everywhere sound amazing instead of gross. Lily hasn't been able to stop thinking about it. Ever since that fateful night at the beginning of break, Lily's mind has been a chaotic mess of need and desire. She didn't expect what happened between them that night, the way James touched her, his fingers sure and gentle, coaxing wild ecstasy from her body with commanding confidence. None of the boys she's been with before ever made her feel so hungry and wanting, let alone with just a couple of fingers. It makes Lily want more, want everything. Compels her to wonder what else James can make feel good, if the soft lushness of his mouth kissing lower and lower will bring Lily to even grander heights.

The thought of some bloke's mouth on her down there creeped her out at first, but for the past two weeks, it's all Lily dreams about. During family dinner and Quidditch games, while they're opening presents and exchanging friendly banter, Lily's gaze finds James's lips. He smiles and laughs and takes great big gulps of mulled wine, and Lily swallows heavily, squirming in her seat, her breath quickening as her pulse races. She thinks he knows what she's been dreaming of. Sometimes, when he's looking at her, his eyes go dark and stormy, before a guilty expression steals the desire from his gaze. He felt so bad last time, he didn't even let her get him off. Lily knows the fact that they haven't had a minute to themselves ever since that night is no accident. James has been avoiding her, but that stops now.

Soundlessly, Lily slips out of her room and into the hallway. She pauses for a moment, listening for any tell-tale noises that would indicate if her parents or Albus were still awake, but the house is quiet. Satisfied, she walks quickly towards James's room, relieved to see a soft bar of bluish light glowing from beneath the door. She figured he'd be awake—James has always been a night owl—and she's glad she was right. Her plan will work much better if he's already up.

She'd knock, but she doesn't want to risk waking anybody else up, and she's not entirely sure James would let her in if she did, so she opens the door and slips inside without warning. Like last time, James is sprawled out on his bed messing about on his Muggle tablet, though unlike last time, it doesn't look like he's watching porn. Pity.

He glances up as the door snicks shut, surprise flashing across his face, followed swiftly by a guarded wariness as he looks Lily up and down. James can't quite manage to hide his appreciation as his gaze skims over the swell of her breasts in the thin nightshirt before lingering on her bare legs, and she suppresses a triumphant smile.

"You've been avoiding me," Lily says after a long moment

James meets her gaze guiltily. "No, I haven't," he lies. "It's the holidays. They're always busy."

Lily rolls her eyes. "You're a shit liar, James."

He flashes her a charmingly rueful smile, and Lily's chest grows tight and achy. "You're right," he agrees, before giving her a hard look. "You know why."

"Yeah, I do." Lily pauses, swallows, her throat dry as she fingers the hem of her nightgown. "I'm leaving tomorrow. I thought you could do something for me before I go."

Hesitation reads clear as day across James's face, but Lily can see the curiosity lurking beneath, the desire. It gives her the courage for the next part as she grips the bottom of her nightie and pulls it up over her head, dropping it in a heap on the floor.

James stares, his throat bobbing as his gaze burns a slow trail down Lily's body. It reminds Lily of the way his fingers felt on her skin, the soft pads stroking over her throat and chest as they made their way south. Lily's fingers hook into the sides of her frilly pink knickers, and a wounded animal noise escapes James's throat as she begins to tug them down, stepping daintily out of them and baring herself completely.

"Lily…" James says, low and rough, half warning, half entreaty.

"I can't stop thinking about it," Lily confesses, soft and urgent. "Nobody's ever made me feel so good, James. I want to feel like that again."

"That's probably not a good idea, sis."

His emphasis on the last word is a clear message, but if James thinks that's going to deter Lily, he doesn't know her that well at all. She steps up to the edge of the bed, reaching out to run a finger over James's lips as James seems to hold his breath.

"You said women like it," Lily whispers, running her thumb suggestively over James's full bottom lip. She can tell James knows exactly what she's talking about by the way his eyes darken. "I can't stop wondering what it would feel like to have you kiss me all over."

"Lily…"

"Please, Jamie?"

He groans, low and full-bodied, sending a shudder vibrating through her as the last of the guilt falls away from his expression, leaving only desire in its wake. He throws the top blanket off his bed and scoots over, patting the free space next to him. "All right then, Lily. Come lay down for me."

She climbs dutifully onto the bed, lying back against the sheets, still warm from James's body. Lily can't help but wriggle against them as she lays her head back against James's pillow. That familiar musky pine tree scent that's always been James wafts up around her, and she lets herself inhale deeply, feeling dizzy and wanting. Her entire body is hot and tight, as if her very flesh remembers just how amazing it felt the last time she was splayed out on James's bed and is eager for a repeat performance. She blinks up at him, staring into his warm, brown eyes as she bites her lip, nervous anticipation making a mess of her insides.

"You sure you want this?" James asks softly, clearly sensing her bout of nerves. "We don't have to do anything, you know." He makes as if to move, and Lily reaches out, gripping his wrist tight.

"I'm sure," Lily says clearly. "I don't think I've ever wanted anything more. I just...I don't know what to expect."

"You liked what we did last time, yeah?"

Lily draws in a shuddering breath as her cunt seems to throbs in remembrance. "Yeah," she breathes.

James grins, and that cocksure confidence suits him so much better than the reluctant guilt he wore earlier. "This will be even better."

Much like the last time, his fingertips trace over her lips and trail down her throat, but unlike before, this time they're followed by James's hot mouth. The kiss is intense, making Lily's belly flip and her skin prickle as James's tongue pries open her lips and slips inside. She's never much cared for snogging, but now she realises that's probably because whatever the hell those boys were doing with her before, it sure as hell wasn't proper snogging. With James, the kiss is slow and coaxing, his tongue stroking along her own in a sensual glide that makes Lily feel giddy and breathless. It's over far too soon, and Lily lets out a mewl of disappointment that has James grinning against the skin of her throat as he begins to kiss his way down her body.

He follows much the same trail as his fingers did that first time they did this, and if Lily thought that felt nice, it's nothing on the hot suction of his talented mouth. James kisses down her throat and across her collar bones before making his way over to her left breast. Lily shudders as he licks up the small swell of her, the skin there so much more sensitive than the rest of her body. When he mouths at her nipple, latching on and sucking, Lily's hands dig into the bedsheets as pleasure rockets through her. Already she feels wet and achy between her legs, and she presses her thighs together, wanting some kind of pressure or friction, something, anything, to relieve the tension building up inside.

James lingers on her breasts for awhile, alternating between the two as he mouths at one and massages the other with gentle hands. He showed her last time how sensitive her breasts could be, but with his tongue and lips and teeth driving her mad, it's clear he has more to teach her about how good this body of hers can feel. She can't believe she ever settled for those fumbling boys at school, the ones who barely even paid attention to her tits, except to slip a hand beneath her bra while they were fucking her, squeezing at them like they were trying to juice a lemon. Lily wonders where James learned it all, if he was just as selfishly clueless as the boys her age when he was back at Hogwarts, or if he's always just been better.

Eventually, James moves on, his lips drifting down Lily's stomach, her belly. His chin brushes against her pubic hair and she clenches in anticipation. His mouth is so close, trailing wet kisses across her skin, making her burn as she imagines what it will be like when he gets…there/.

He presses a final kiss to the top of her thigh, before pushing himself up and placing a hand on Lily's knee. His touch sends shivers exploding across her skin, and Lily swallows as he looks at her with hungry, serious intent. Slowly, he tugs at her, easing her legs open so he can move between her spread thighs. Lily's face heats as big, warm hands circle her ankles before moving slowly up her calves, her knees, before his thumbs begin to rub at the sensitive skin of her inner thighs. She's so open like this, bared to James's gaze, cool air hitting her where she's wet and slick. James looks at her shamelessly, showing Lily with his eager gaze just how much he likes what he sees. It's empowering, and a little scary, being so visible. Despite her frequent liaisons, she's never had much opportunity to get properly naked with any of the blokes she's been with. Frankly, she's not sure she could have done it, bared herself so brazenly to any of those meaningless lays. James is different. She trusts him, knows he won't take advantage, won't do anything to hurt her. Quite the opposite in fact.

He looks up at her then, that familiar cocky grin crossing his face as he bends over to place a messy kiss right beneath her belly button. She laughs and squirms beneath him.

"James!"

"Just checking if you were still ticklish," James says with a wink. Before Lily has a chance to respond, he flops to his stomach between her legs, his mouth dragging across her lower stomach towards his prize. He noses at her pubic hair, and it's amazing how just the faintest pressure against the hair follicles there sends little bolts of pleasure straight to her groin. It's like they're directly connected to that twinging, unsatisfied place inside of her that's desperate for more.

James looks up at her, his face just inches away from her cunt as he breathes in deep. Lily feels herself flush with squirming embarrassment as wetness further slicks her thighs. She doesn't see how it could possibly be pleasant, that pungent, slimy wetness. Apprehension flashes through her, and she tries to close her legs, suddenly anxious about the idea of James’s face rubbing against her sex. Of course, it's impossible to close her legs with James's broad shoulders pressed between them, and James's expression when he looks at her is kind, if slightly amused.

"I know you don't see the appeal of this, Lils, but trust me, I like it," James says, somehow managing to hone in on Lily's fears. "You smell good." He takes another deep inhale and licks his lips. His eyes smoulder. "Bet you taste good, too. Let me find out?"

It's clear he's offering her an out, that if she really feels too uncomfortable he'll back off. There's definitely a small, nervous part of her that likes the idea of that, but Lily has never been one to shy away from a challenge, and she's far too curious to turn back now. There's nobody else she trusts enough to give this to her.

"Yeah," she whispers. "Okay."

James leans in and blows a hot puff of air along her sensitive slit, making Lily shiver. It tickles and it feels good, but it's not enough, just a tease, a promise of better things to come if she can just get…

Something strong and soft and pliable slides over her cunt, and Lily's legs twitch as pleasure wipes out all other thoughts. She looks down her body to see James's auburn curls between her thighs, his eyes closed as his tongue licks at her opening, before steadily moving up and up and up, straight towards that little button of euphoria James had introduced her to last time. Her stomach muscles tense in anticipation. The firm point of James's tongue flicks teasingly against the nub nestled at the apex of Lily's thighs, and pleasure jolts through her, sharp and almost unbearably intense. Her legs try to squeeze shut on instinct, trying to protect her body from the overwhelming assault, but James's hands press firmly against the meat of her thighs, pinning her down like a butterfly on a board.

That same wild pleasure she felt the last time she was with James begins to build inside her as James licks and sucks. His tongue strokes a purposeful beat against the heat of her, some unfamiliar rhythm clearly meant to drive Lily mad with desire. It's working, because Lily feels like she's losing her goddamn mind, her hands fisted in the sheets, head thrown back as she pants through the ecstasy threatening to take over her body. Her chest heaves with the force of her ragged breaths, her breasts bouncing as her body undulates against the mattress. She remembers this feeling from last time, the wild vastness of it, the way it takes her over as the crescendo builds and builds. Every flick of James's insistent tongue encourages the untamable need inside her to unleash itself. Lily finds that she both fears and craves it, half worried she might lose herself in the riotous pleasure, but fully willing to take the risk if it means she gets to experience that moment of rapture once more.

Without her permission, one of her hands snakes its way into James's hair, urging him more firmly against her. He makes a small sound of pleasure, a little hum that vibrates against her sex. It startles her into looking down her naked body to where he's latched on to her cunt, his mouth working her over. His eyes are open, and he's looking up at her as his tongue continues licking at her clit, wet and filthy and so much hotter than Lily could have imagined. It makes Lily's heart skip a beat, her chest tight and hot at how good he looks giving her pleasure. He keeps his gaze locked on her own as he wraps his lips around the top of her folds and sucks, his tongue darting over the crux of her, fast as a hummingbird's wings.

Lily's loud when she finally pitches over the edge and falls into the sea, her orgasm drowning her in elation as she bucks up against James. Her fingers dig into his hair so hard it probably hurts, but her joints feel frozen and locked up, like her body isn't quite sure how to properly function after being overloaded with so much pure, undiluted pleasure. James doesn't make a single sound of protest, just licks at her, soft and soothing, each swipe of his tongue sending little bursts of razor-sharp pleasure slicing through her skin. Eventually, her heartbeat begins to slow, the overwhelming buzz of bliss fading into a warming glow. Her body begins to function again, muscles relaxing against the bed as she gently eases her fingers out of James's hair. James grins at her in thanks as he rubs at his head and pushes himself up to his knees. His mouth and chin are shiny with his spit and her slick, his eyes dark and glazed with lust, reminding her that he's yet to get off. Lily's eyes immediately hone in on the thick ridge of his erection, clearly visible in his grey joggers.

"Are you going to get off this time?" she asks him plainly. He wouldn't let her see him, before, but Lily doesn't plan on letting him get away with it a second time. James hesitates, guilt already beginning to edge into his expression, and Lily glares. "Sorry, I didn't mean to phrase that as a question. What I meant to say was, you are going to get off this time."

James's eyebrows rise in obvious amusement, self-recrimination fading into the background. "Am I now?"

"Mmhmm," Lily hums before tossing him an impish grin. He's clearly a bit skittish about the idea of reciprocation, and Lily has a feeling he'll baulk if she suggests she help make him come. Baby steps it is. "I want to watch you." When he hesitates again, she widens her eyes and looks up at him beseechingly. "Please? Won't you let me see?"

James groans and grips himself, before nodding. He bites his lip as he shoves his joggers down mid-thigh, and wraps a fist around his throbbing cock. Lily gasps as he begins to work himself over, fluid pearling at the tip of the flushed shaft. She's never really seen a prick so close before. Her previous liaisons were generally frantic and harried, the blokes only pulling out their cocks so they could slide them inside her fanny, usually taking her from behind. Lily hasn't much minded the lack of pricks waving about—she's never had any interest in seeing the weird things up close and personal. Now, though, she finds herself strangely captivated by the sight, overcome with the urge to touch, and, even more bizarrely, to taste. She remembers James mentioning, before, that sometimes women enjoy returning the favour, using their mouths on men the way James just used his mouth on her. Before, the idea had filled her with horror, but as she watches James's fist fly over his cock, his expression furrowed with pleasure, curiosity begins to prickle within her.

Even though she just came, watching James fuck into his fist makes something inside her ache to be filled. She's never felt that way with any of the other boys that had her, but Lily's belly shivers at the thought of James being inside her. Merlin, if James could make her feel so amazing with his fingers and his tongue, how good could her make her feel with his cock? She wants, wants in way she's never, ever wanted before, and the feeling only intensifies as James comes with a shuddering cry. James's come stripes her chest and stomach with pearlescent white, his release dripping down the curves of her breasts and pooling in the dip of her belly. James eyes his marks with a possessive kind of hunger, his eyes gleaming as he looks her over. Despite her nudity and the vulnerability of her position, that reverent look in James's eye makes Lily feel powerful, a heady rush of adrenaline shooting through her veins.

That's why Lily started having sex in the first place, after all, for the power it gave her over the silly boys at school, but James has shown her just how much she's been missing. Lily's been playing with a bunch of rookies, enduring their grabby hands and awkward poking because she didn't know it could be any different. Things have definitely changed. There's no way she can go back to that awkward fumbling, not now that she knows how much better it can feel, that she can actually enjoy it.

James cleans them both off with his wand, ever the gentleman, and this time he doesn't even try to convince Lily to go back to her room. Instead, he sets an alarm charm for the crack of dawn, tosses Lily her nightie, and holds open the blankets with a resigned smile. She scurries under them, craving closeness in a way that's a little foreign and uncomfortable. With other blokes, she couldn't wait for them to leave, but her body feels sleepy and sated in the wake of all that pleasure James just gave to her, and all she wants now is to curl up against him and let sleep take her.

James offers no objections, running a drowsy hand through Lily's long hair as she tucks herself against his side, her cheek resting on his chest. A part of Lily is dismayed that she's returning to Hogwarts tomorrow, that she doesn't have more time to grind away the last remnants of James's guilt and convince him to show her all the other wonders she's now realising sex has to offer. The disappointment fades quickly though. Lily is nothing if not determined, and she can be patient, when she needs to be.

Easter hols are just a few months away, after all.