They've never really talked about it. Not out loud, not in so many words. Mal doesn't, ever, not when she can avoid it and sometimes even when she can't, and Evie wouldn't know how to open the subject anyway so it's probably for the better that Mal doesn't.
She doesn't need the words. She knows that sounds like something you'd say if you did need the words and were trying to deny it but seriously, she doesn't — the important thing with Mal is never the words, Evie's known Mal long enough to know that. When she makes fun of Evie for being a princess that isn't the part that matters; the part that matters is how she'll go out of her way to get the nicest fabric out of the scrap heap when the barge comes in, is the portrait of Evie smiling next to Mal and Jay on Mal's wall, is the extra blanket she keeps for the nights when Evie can't stay in her mother's castle, because Evie gets cold at night in Mal's concrete loft.
The part that matters is, on the nights when Evie can't stay in her mother's castle, Mal is there, with warm open arms and a soft place for Evie to escape to.
Tonight is, of course, one of those nights; Evie's mother doesn't have tutors come every day anymore, Evie's too old to need that and it's past time she started building status and connections on her own, but that doesn't mean they don't come ever, and she never did like the way this tutor looked at her and it's only gotten worse since she started growing breasts and she knows she can handle it but it's just better to have Mal. Mal looks at her — honestly not that much differently, but it feels different. Still possessive, but in a way that makes Evie feel like a person Mal wants to keep, not a thing she wants to eat.
Evie knows Islanders don't usually spend fabric and energy on clothes just to sleep in, knows that her mother's insistence that princesses do not sleep in the buff is the exception rather than the rule, but it hasn't been long enough that it isn't still startling to see Mal bare. Her skin is warm through the fabric of Evie's dress, and her voice is warmer when laughs and tugs at the neckline and says "You're such a princess, E, take this off," and Evie strips for Mal with the same motions she uses to strip for her tutors but it's different, it's different, when Mal watches her eyes glitter and Evie feels warm and strange and not scared or even nervous at all, and the air is still cold on her bare skin but it's different with the blankets and Mal's warm hands and the promise of Mal's warm body.
Some nights they just hold each other, Mal's skin against Evie's, Evie's forehead against Mal's, their arms draped over one another. Some nights Evie curls herself around Mal and buries her face in Mal's hair and wraps her arms around Mal's waist and Mal lets her, and they fall asleep with Mal's back against Evie and Evie's chest against Mal.
Tonight isn't one of those nights. Mal's eyes are still glittering; she pulls Evie closer too quickly for it to be for warmth, puts one hand on where Evie's hips are just starting to develop. (She'd start bleeding soon if she were in Auradon, but girls bleed later here, according to — but Mal's hands are on her hips and it doesn't matter, nothing matters but the way Mal is smiling, the warmth of Mal's skin, the heat that pools in Evie's thighs —)
Evie has been taught, painstakingly, how to react when she's touched, when to shiver and when to sigh and when to tip her head back and when to close her eyes. With Mal all those lessons fly away as soon as they touch — she gasps at the wrong moments, pulls Mal closer before it's time — and Mal just laughs and smiles that pleased glitter-eyed smile and keeps touching her, runs her hands up Evie's ribcage and touches what breasts she has and smiles wider at the whimpery sound that Evie doesn't stop herself from making.
She's been taught to keep quiet, to focus on the boy she's with, to give him what he wants; she hasn't been taught what to do when Mal presses into her and takes what she wants and gives Evie everything she would think to ask for if she could form words, hasn't been taught how to respond when Mal doesn't need to be given anything because she knows Evie is already hers. She's clumsier with Mal than she is with her tutors, clumsier from lack of teaching and lack of practice; Mal doesn't seem to mind, and if she does mind she doesn't do anything but lean down and kiss Evie more, deeper, take what she wants to take and give what she wants to give and no more and no less — Evie has been taught how to fake an orgasm, how to squeeze her eyes shut and which muscles to tense; with Mal she learns how to bite her lip to keep quiet through a real one —
It lasts as long as Mal wants it to last. No more, and no less. It could be frightening but it's comforting, instead, that Evie doesn't have to worry about how much to give, that Mal can handle knowing how much to take.
"Evie," she whispers, when Evie comes back to herself, and Evie almost thinks she knows what's going to come after it, and instead Mal whispers, "My father is Hades."
Evie had opened her mouth to give the right response to the words she thought were coming, but she doesn't have words for this. She closes her mouth and feels a little bit stupid for having had it open in the first place.
"You're the only one who knows," Mal says, and she isn't glittering now, she's as close to earnest as Mal ever comes, and Evie still can't think what to say so she nods, mute, and holds Mal closer while they both fall asleep.
She doesn't need the words. She still doesn't need the words.
The words aren't the important part, with Mal.