On Saturday night, Mikasa crawls through his window, a beautiful pile of tangled limbs. Eren knows he should tell her to go home, to come back tomorrow when it's daylight. Her parents will be livid in the morning to find she's not in her bed and he doesn't want to begin to imagine the lecture he will (yet again) receive when his parents open his door to say good morning and find their bodies entwined. (His parents love her—in fact, have often said they would adopt her if they could—but don't particularly want the two twenty-year-olds sleeping together in the same bed.)

Tonight she's in tight jeans and a simple white tank top, her hands holding matching white flats. "Your grass is wet, they'd get muddy," she says when he asks why she isn't wearing them. He's about to point out that instead of her shoes being dirty it's now her feet, but she's already wiping them on the oval rug near his bed and he finds it would be pointless to mention it. Without much discretion to his room and her surroundings, she drops the flats next to his bed.

She unbuttons her pants and slides them off, folding them neatly and placing them on his desk before climbing into bed with him. He tries hard not to stare at the white ribbon bow on the front of her underwear, tries not to let his mind wander to what's beneath the thin piece of clothing.

As she's laying on her side, eyes turned to him, he takes her in; he looks at her pretty almond eyes and inhales the scent of Mary Jane and tobacco, laced with the scent of a party she's just come from that he will never know the events of. Her lips arch into a smile, curling a little at the corners. They seem especially pink tonight and he hopes it's from remnants of chapstick and not from being kissed earlier in the evening. She leans in and pecks his cheek, murmuring, "Did I wake you?"

It's a rhetorical question because she knows he goes to bed at ten every night and it's now twelve-thirty. She knows his schedule like the back of her hand; though, he supposes, she ought to after so many years of friendship.

Twelve years of friendship spans between them. Having known each other since the young age of eigh, time has given them plenty of opportunities to learn each other's quirks. He supposes he's been in love with her as long, too, but he can't ever really place a time when he didn't love her and then the moment when he did. He simply does and he has never particularly bothered to question it.

"No," he finally answers as she leans in again, this time kissing the corner of his lip. He inches his body closer to hers; so close that when his eyes glance downward he can see her breasts, small but giving the appearance of being fuller than they are in her push-up bra. He'd told her once that he liked her better in the black lacy one with a pink bow, the one that had no extra padding and didn't deceive the eyes, but she'd only shrugged and said she wore her clothes for her pleasure and no one else.

They love each other, but they're not in love with each other, because love takes two people and Eren is only a single person. But, sometimes, they fuck like they are and Eren's always left in a whirlwind of her smiles and perfume. Sometimes she stays, sometimes she goes, but the worst are the mornings when he wakes alone with empty arms after a night spent rolling in the sheets with her. Undeniably, he wishes she would always stay before sunrise and never leave his bed, but asking her to stay is out of the question. She's like the wind: transient, mostly unpredictable, and far too capricious.

"Liar," she says quietly, as if his parents can hear them, despite Eren's room being on opposite ends of the hall. "You go to sleep early every night. Maybe in a past life you were a sloth."

"Maybe," he agrees, feeling for her hand on the bed and smiling when hers finds his first. "You would've been a fairy."

"Those aren't real," she answers, inching closer so they're sharing the same pillow now. Her eyes seem heavy but focused, never wavering from his gaze. Eren's eyes flicker downwards for only for a moment and he catches sight of a hickey he'd missed before; it's tucked underneath a strap and he'd overlooked it earlier.

It's not the first time he's seen one on her and he doubts it'll be the last. He's spent more time than he'd like to honestly admit to trying to memorize her body and he knows it well after so many years. He knows all the freckles on her shoulder, had tried to help her count them one hot summer night when they'd been in nothing but underwear. He's kissed the dimples on her lower back more times than he can remember. But sometimes she forgets he has feelings or perhaps chooses to think he doesn't care and, every so often, she shows up with remnants of other lovers.

Tonight is one of those nights.

He breaks his hand away from hers, reaches out to trace the bruise, thinks of the times she's come to his bed tipsy and smelling of cheap cologne. He remembers the times he's undressed her, gone to worship her body, only to find love bites beneath her breasts, bruises on her hips, teeth marks in odd shapes between her thighs. He's never able to continue on these nights, always goes soft and pushes her away. She's never addressed his demeanor change but her lack of confrontation leads him to believe she already knows how he feels—she's always so calm and quick to wrap soothing arms around him while whispering, "Eren, I'm really sorry," but never does she attempt to elaborate on what it is she's apologizing for.

This time is no different and Eren is glad they have not gone farther, that he's able to see her antics before they've gotten each other too worked up. It's different tonight, however, because as Eren finds himself pulling away, he feels Mikasa's hand seek out his once more. He watches her lips rest in a way that indicates displeasure, her eyes furrowing as she looks for the right words to say.

There are none, Eren knows, but he will let her try anyway.

"Sometimes," she says, so quietly and slowly he knows she's picking her words carefully, "I think I was meant to be born in another place."

"Like in a different era?" Eren keeps his voice level, because acting upset will not help the situation in the least, despite the hurt he feels swelling in his chest like cold water.

"No," she says, shaking her head. "I was born in the right time, but not the right place. Like I should've been born underwater or in the sky. Maybe on Saturn or beneath a grave."

"Places that are…unusual," Eren says finally. He watches Mikasa pull her lower lip between her teeth, drag it back and forth. He hates himself for wanting to kiss her once more. She could not have been a fairy in any past life for she would have certainly been a siren instead, luring in men with ease.

"I don't know who I am sometimes," she says, her voice below a whisper now, words intentional, "and I can't love anyone until I know who I am first."

He supposes he should have suspected as much from her, a vague answer to a question he has not asked (Do you love me, too?) but her words do not temper the hurt. They don't quell but they help, however minimally, and he reaches out a forgiving hand to swipe his thumb across the lower lip she has been worrying.

I forgive you.

It's a testament to their long-standing friendship that he does not need to verbalize his statement for her to understand it. She releases his hand for only a moment to draw up his comforter around them, lacing their fingers once more after. With gentle tugs to his hand she maneuvers him so they're facing each other on his pillow again. When she leans her forehead in he meets her half way, unable to resist the last affection of kissing her nose before they settle down. It's cute to him the way her nose crinkles for a brief second before she smiles and closes her eyes; he knows she will drift off first because she is always running at full-speed so when she stops for a moment to rest, she always crashes hard.

When his eyes can stay open no longer, Eren knows before they have closed that this is a night where she will not be in his bed come morning. She will leave and his window will be left open, curtains cast aside to be blown by a breeze that will pass through his room. It will sting him to wake alone, as it always does, but like any siren worth their salt, she will surely come back another night to sing him to sleep once more.