Disclaimer: These characters do not belong to me.

Notes: Modern-day no-powers AU: Raven is Charles's older sister and Erik is her best friend from college, and Charles develops a desperate crush on Erik that evolves into something more. For anyone who might be worried: Charles meets Erik at 15, but they don't have sex until Charles is 18.

Raven is six years older than Charles; Charles has never really considered this age difference vitally important in one way or another, except to decide that even if Raven were six years younger than Charles, she would probably boss him around in the exact same way. He doesn't really think much of the difference between fifteen and twenty-one, until Raven comes home from college for a study weekend with her new best friend in tow, introduces him cheerfully as Erik Lehnsherr, and Charles finds himself falling head-over-heels into a train wreck of doomed lust.

Erik is tall and lean, all sharp angles and strong hands and a waist that Charles can't take his eyes off of; his voice is low and rumbling and male, hits Charles square in the stomach like a fist, and Charles holds his hand out and says, "Hello, I'm Charles," hoping desperately that he doesn't look as slack-jawed stunned as he feels, that he sounds adult and not like the little boy of fifteen that he is.

Erik takes his hand, firm grip, dizzying warm touch, and his mouth quirks as he says, "Erik. It's a pleasure to meet you, Charles." He lets go after a stretch of time that is both far too short and agonizingly long, and disappears into the house with Raven; and then, and only then, does Charles remember to breathe.

What follows is a long two years of helpless attraction on Charles's part whenever Raven and Erik come home. They're out of college now but they're working very nearby, and while Charles's mother might not care much about who comes and goes at home, Charles is always eager to see his sister and her best friend, so they visit often and stay as long as they can.

Charles asks Raven once, early on, if she and Erik are dating, and is immeasurably reassured when Raven bursts out laughing.

"Oh, god no," she says, still laughing as she speaks. "He's my best friend. I mean, not that he's not hot, because I've got eyes, but I like 'em a little less 'tall, dark and broody', you know?"

Charles doesn't know, because all evidence points to 'tall, dark and broody' being exactly his type, but he smiles anyway, and curls into Raven's welcome half-embrace.

Instead of his attraction fading, Charles finds miserably that it only seems to intensify over those two years, because Erik is not just so effortlessly gorgeous that Charles has to jerk off twice before each time Erik visits so he won't embarrass himself, he's also intelligent and sarcastic and sweet when he thinks no one is paying attention, and he listens so intently when Charles talks that Charles feels a little faint, and he never, never treats Charles like a child.

Sometimes, when Charles's mother has been in bed for most of the day with a headache, Charles takes his homework over to Raven's apartment and spends a blissful evening there and sometimes the night as well. Erik is usually there, too, sitting sprawled on the couch with a book propped on his thigh and half his attention on the television. Raven works on her laptop and pokes Charles every once in a while and yells at the TV whenever someone enters an unlocked house by themselves or otherwise does something that proves them too stupid to live; Erik laughs at her and slouches lower in his seat, legs falling further open. Charles buries his face in his textbook and steals glances at the line of Erik's cock in his jeans, thinks about kneeling between his open legs and putting his mouth right there, feels his mouth flush wet with hunger.

"This is how we know your sister never cleans this couch," Erik says one time, voice low and amused, before he reaches out and rakes his fingers through Charles's hair with no warning. Charles freezes, breath catching in his throat, and then he sees the shred of the fabric softener sheet that had apparently been caught in Charles's hair, now twisted in Erik's fingers. "Unless this is a fashion statement?" Erik asks, eyebrow arching, and Charles coughs to clear his throat.

"No, it's definitely Raven's fault," Charles says, inordinately proud of the way his voice doesn't waver one bit, and Raven makes a rude noise and pushes Charles's head down into the couch and tells Erik, "Oh, you're one to talk, I've seen your place. You're supposed to get rid of the dust, not make friends with it, you know."

Erik shoots something back in response, but Charles has stopped listening at this point. He turns casually over onto his stomach and picks his book up again, trying to hide the fact that he's gone half-hard from just the feel of Erik's fingers in his hair and the searing heat of his focused attention.

For a seventeen-year-old perpetually caught in the throes of teenage hormones, Erik makes life difficult, to say the least.

Charles knows this is all hopeless, and most likely just an exceptionally persistent crush due to proximity that will fade away with time, and someday in the future Charles might even confess it to Erik and blush and accept his good-natured ribbing, but—

Charles is almost certainly imagining it, but he thinks that slowly, something has changed in the way Erik looks at him.

Charles has grown less than he'd like in the last two years, but he has grown, lost a little roundness in his face, limbs lengthening, and the mirror tells him that he's not half-bad looking. He's somewhat attached to his hair, actually. Occasionally he gets a look or two that he recognizes, that makes him flush a little, that he never really ends up going after.

The one time Charles comes over in a pair of jeans that are a little too small but he wants to get some more wear out of, and a button-down shirt that he's been told is the exact color of his eyes, Raven looks at him for a moment like she's seeing him in a new light and says, grinning, "Looking good, little brother. Any romantic prospects on the horizon?"

"Yes, I'm beating them off with a stick," Charles says dryly, and Raven ruffles his hair and mockingly pinches his cheek and tells him it'll all come with time, no rush, while Charles scowls and tries his best to duck her hand.

Erik says nothing, but his gaze stutters before he meets Charles's eyes, a momentary hesitation, and for an instant—one fleeting, blink-and-you'll-miss-it instant—Charles sees something in his face that makes his mouth go dry and his heart start pounding in his chest.

Erik looks away and makes a dry comment and the moment is gone, but Charles tucks the memory of it away, buries it deep in his chest, a small spark of hope he will let himself nurture, unwise though it may be.

"Have a good night, dear," Charles's mother says distractedly when Raven and Erik are over one evening, and then she disappears into her room with a glass of wine and not even a backward glance. Raven is berating someone she works with over the phone in the other room. It's not even eight PM.

Charles doesn't look up from his book, but he can feel his mouth crumple a little at the corners, an old dull hurt thumping inside him at the fact that he can't remember the last evening he spent with his mother's full attention on him.

There's a rustling from behind him, the sound of Erik shifting awkwardly, and then Charles feels a hand brush tentatively over his hair. For once Charles doesn't let himself think; turns his head to the side and traps Erik's hand between his face and the back of the couch, giving into selfishness for a moment and taking the comfort he wants, eyes sliding shut. Erik's hand is still for an instant, before he runs his thumb through Charles's hair and then his other fingers over Charles's face, a stuttering caress. Charles's throat is tight. When he blinks, he can feel his eyelashes brushing Erik's palm.

Erik makes a low, inarticulate noise, and tightens his fingers before he draws his hand away.

Charles doesn't want to open his eyes and look up, but he forces himself to do so. Erik looks a little uncomfortable, but somehow Charles can tell it's more self-doubt than anything else, as if he's unsure if he even helped at all.

Raven comes into the room at that moment, so Charles doesn't say thank you, but he has a feeling that his heart is in his eyes and Erik has heard it anyway.

Erik still listens intently when Charles babbles about his science classes and how he wants to go into genetics, but now he does so with a strange look on his face—it's a little like the look Charles has caught on Raven's face more than once, the one that recognizes that Charles has actually grown up now, only on Erik's face it looks more taken aback, a little like a revelation.

Erik doesn't throw his arm around Charles anymore, doesn't ruffle a hand through his hair, doesn't clasp the back of his neck with one hand and leave it there for a minute or two, and Charles tries not to miss it, the easy physicality Erik used to share with him. Erik is more careful with his touches, but Charles considers it an even trade for what he gets in return: a slow dawning light of change in Erik's eyes; the new weight of his gaze, lingering over Charles's body; the momentary stumble of Erik's perpetually sure feet when he sees Charles stretch his arms, shirt riding up to bare his waist, an invitation on Charles's part, if Erik is inclined to accept it.

Next to Erik, Charles feels so thoroughly young, all arms and legs and clumsiness, palpable want and awkward words, so obvious it hurts; but Erik has never looked at Charles like he's too young to be worth something, and the way he looks at Charles now—

Charles is not imagining it; but he knows better than to accept a theory without testing it thoroughly first.

More than one of the looks Charles has been getting at school have been aimed at his mouth; sometimes when Charles is in his room, he puts two of his fingers in his mouth and swallows around them as he fists his cock, imagines what it would be like to suck Erik's cock with Erik's hands in his hair and Erik's voice resonating in his ears. After Charles has come, he catches sight of himself in the mirror, his mouth sloppy-wet and pink. He looks like someone who would be good at sucking cock and would love it, too.

The next time Erik and Raven are over, Charles checks out of the corner of his eye to see if Erik is looking at him, and then swipes his tongue over his lower lip before sucking it into his mouth, feigning concentration on his homework. Erik's jaw clenches. Charles pops his Diet Coke open, licks the wetness off his thumb in a long slide, then casually looks to see Erik's reaction.

Erik is staring down at his lap. The back of his neck is flushed pink, and his fingers are so tight around his own thigh that his knuckles have gone white. Charles can practically feel the air crackling around him.

Charles excuses himself to the bathroom, where he bites down on his free hand and jerks himself off with the other, and comes so hard he thinks he's broken something.

Charles lies awake one night, listening to the sound of footsteps below him in the kitchen pacing back and forth. His mother won't be woken for love or for money, and Raven is a thoroughly sound sleeper at night, but Charles didn't need to know either of those things to know that it's Erik moving around downstairs. Of course it's Erik.

Before Charles can talk himself out of it, he gets out of bed and strips off his shirt, sets his hair aright, and trips lightly down the stairs in just his pajama pants. He's flushing already with a dizzy mixture of nervousness and anticipation and lust, heart pounding with how stupid this is, christ, it's like something out of a seduction how-to, one of those magazines at the checkout aisles, he'll be lucky if Erik doesn't just laugh him out of the kitchen where he stands.

But everyone else is asleep, and Charles knows the intimate sound of Erik's restless feet at night from two years of listening to it like a heartbeat, and Charles just wants to be reckless, for once.

Erik turns as soon as Charles steps into the kitchen, all fine-tuned reflexes, and Charles is concentrating so hard on looking as casual and unruffled as he possibly can that he almost misses the dip of Erik's eyes, a hot slide over Charles's body, and the way his throat works when he swallows.

Almost.

Charles smiles in greeting (feels it tremble at the edges), turns to get a glass out of the cupboard, and he says over his shoulder, "Couldn't sleep?"

Erik is watching the curve of his back, Charles knows it; even when he's looking at the cupboard, his skin prickles under the weight of Erik's gaze. Charles goes hot all over, knows the back of his neck is pink.

"I had some trouble, yeah," Erik says at last, and his voice is controlled, but there's an audible rough edge to it, and Charles can't help his shiver at the sound. "And you?" Erik continues, as Charles fills his glass with cold water, hoping it will cool the flushed burn of his body. Erik's eyes fall to Charles's bare chest again and linger, this time. He meets Charles's gaze afterward, as if waiting for an explanation.

Charles drinks, slowly, sets his glass down and sucks water off his bottom lip. Erik's mouth is parted softly, and he isn't blinking at all.

"It's a little warm in my room," Charles says quietly, but there's a waver in his voice, fuck he sounds too young, and something in Erik's expression cracks open at that because he can't play clueless anymore, can he, and he says, "Charles," a plea, a warning, Charles doesn't know, and Charles—

Charles kisses him.

Just gets up on his toes, braces a hand on Erik's firm chest, catches his half-open mouth and kisses him the way Charles has wanted to for years, because if he doesn't take his courage in hand and jump off this cliff now, he doesn't know if he ever will during this lifetime.

Charles expects Erik to shove him back, maybe, or perhaps kiss him chastely and then turn Charles gently away.

He doesn't expect the way Erik opens up for him like he needed it as much as Charles, or the broad hand that rests at Charles's lower back and pulls him in closer, a searing brand against Charles's bare skin. Charles has wanted so much he couldn't stand it, but he never expected to get even this much.

Erik nips at Charles's lower lip and then pulls it into his mouth, tonguing the curve of it repeatedly until it feels tender, like the skin of a plum; Charles is hard, blushing from the wet gasping sounds he can hear himself making, and he wants, oh, he wants to see his cock disappear into the tight clutch of Erik's huge hand, he wants Erik's fingers to slide beneath his waistband and touch him any way he likes, he wants to fall to his knees, he wants everything.

Erik groans into Charles's mouth, brings his hand up to cup the back of Charles's neck, and finally pulls away. Charles makes a noise that is embarrassingly close to a whimper and tries to get at his mouth again, and Erik, in an apparent fit of weakness, lets him do so for a moment; but Charles has barely gotten the taste of Erik back on his tongue before Erik yanks himself away again, letting out a helpless sound, stepping backward and looking as though the physical distance is all that is keeping him from throwing himself back at Charles.

"Charles, I—we can't," Erik says, fisting his hands at his sides. He is the picture of a man torn between two violently warring impulses.

"Don't tell me you don't want to," Charles says, in an inexplicable rush of equanimity, as if the sight of Erik's uncertainty only bolsters his own resolve. "You've never lied to me before."

Erik visibly hesitates, before saying quietly, "Then I won't start now. But Charles, you've only just turned seventeen, and you're Raven's baby brother, and—" He's clearly searching for the right words to articulate just why this is such a bad idea, and all the while he's staring at Charles's mouth like the only thing in the world he wants to do is reach out and touch.

Something in Charles tells him not to push. Not now.

When Charles says nothing for a moment, Erik shuts his mouth, reaches out and runs his thumb over Charles's cheek, and says, "I'm sorry, I—good night, Charles." In a less controlled man, one might call his retreat from the kitchen 'running away'. Charles is sure that in Erik's head, he's labeled it a tactical retreat.

Charles touches his own mouth with two fingers, feels the swollen, wet curve of it, and smiles to himself. Erik is running scared, because he wants this—he wants Charles and doesn't know what to do about it, and now that Charles knows that for certain, everything will be fine. He only has to wait for Erik to catch up.

Charles is very good at biding his time. He's waited this long; a little while longer won't kill him.

Heading back to his bedroom, Charles wonders idly if Erik would appreciate that old t-shirt he hasn't thrown away yet, that fits a little too tight across Charles's chest and bares a few inches of his stomach and is worn so soft you can practically see his nipples through it.

Charles is willing to wait, but no one said he can't cheat a little while he does.