Here's the thing: they love her.
They loved her as a squalling infant, as a toothless scamp, as a coltish young girl growing into her things, as a child shuddering at the touch of her first period. They loved her when she donned men's clothes to go hunting for them, and they loved her when she sighed about pinnces over her embroidery.
They loved her, so they stayed when the castle fell into sleep, when the thorns rose up, when the roses choked the air with their sickly scent. They loved her, so they returned to their old glistening forms for fear that a human body would be more vulnerable to the curse.
They wept delicate little tears over her body, begging forgiveness. They carefully undid the knots in her hair, planted little kisses on her rosy cheeks, arranged the delicate folds of her skirt. They told her they would stay as long as she needed, a binding promise of the kind that fey usually try to twist out--but not them, not ever.
So they stayed. They stayed, as the seasons turned in the world outside while the castle itself remained untouched. They stayed, surrounded by the living dead, bodies trapped in static. They nuzzled into the silky coils of their princess' hair and waited for her hero to come.
Problem was, he didn't seem very interested in showing. The men who did come were brutes, their steps haunted by dark deeds. The fairies saw them coming and let them be shredded on the thorns, their bones left to hang as a warning. Others were simply mad, and were gently turned out by prodding leaves.
So they waited. Waited. Waited. Waited. Waited. Wait--
And then, well...it's not quite right, perhaps, to say that things changed. The change was just so slow that none of them could see it until it was too late.
The mind of fairies tick differently from humans, even good, kind fairies like hers. They have to work hard to remember what is good and evil, what is right, what is proper. They have to try to remember who this particular human is to them, because sooner or later they will forget. Immortality is not good for one's memory.
Keeping it together is a lot of effort, and at some point they just have to...stop. Stop remembering, stop trying so hard to preserve the human aspect of their selves, stop losing themselves into fussing about boundaries while they could be fussing over their beautiful princess.
And, well, they're bored. It is always so dangerous for fairies to get born, even the ones with the best intentions. And they are there for so long.
They love her. They love her, but as time passes they start forgetting about the ways they loved her before and begin to focus more on what it feels like to look at her now, to gaze upon her golden hair, to caress her pale skin, to trace the rise and fall of her breast.
So maybe it doesn't matter when, exactly, their little kisses and pats stopped being quite so chaste. Maybe it was as inevitable as the fall of rain beyond the castle walls, as the prick of fingers upon spindles and the mad cackle of witches.
They kiss her on the throat, one by one. They nuzzle up under her musty clothes, rubbing her over her tender flesh. Her breasts are small, trapped at sixteen like the rest of her, but the fairies like tending to them anyway, rubbing their small bodies against them.
They spend hours exploring her little pussy, their giggles bringing the first light back to the dark, lonely castle in years. They learn her body better than she did and easily push her towards her first orgasm. She trembles on the bed, and they lap up every drop of her fluids like precious nectar.
Does her breath hitch ever so slightly at their touch? Does she sigh as they drag their tiny teeth over her collarbone? It's truly impossible to say, but nevertheless they grab on to all the little half-noises as proof that it's alright, that their princess wants this. That it'll even help her, maybe.
So they keep it up. She is their special girl, she always has been, she deserves the best care. They trace their tiny fingers over her veins, tracking the flutter of her pulse. They whisper ancient secrets up against her skin, one murmuring about untold murmurs in her ear while the other two play with her cunt below.
Their princess doesn't wake. But sometimes she smiles, and sometimes she sighs, and if they just push a little harder, go a little deeper, she'll wake. And then...and then.
Well, it doesn't matter, does it? She'll always be their tasty little princess.
Their wayward sister visits, once. She stands outside the thorn wall and tries to taunt them, mocking them for chaining themselves to one weak little human. She asks them how long it has been before the last prince came, asks what welcome he might receive from these sweet little fairies if actually got inside.
How good are you now? she growls.
The fairies have no answer. To be honest, they don't really care. "Good" and "Evil" are labels from so long ago, buried deep by time and tide. They send protective pulses of magic through the castle walls, the magical equivalent of a threatening growl.
Their sister sees that there is no fighting them now, not when they have unclamped themselves from the quiet trap of respectability to unleash their full, raw power. She lets out a huff, and leaves them be.
It's just the fairies and their princess, now. Their princess, whose true name they can barely remember by now.
She does not age, unlike so many others of her kind--even the bodies in the castle have started to rot and decay, the magic sucked dry by the fairies' need to direct more, more, more energy at keeping their treasure safe. She will stay safe, untouched, and beautiful.
She will offer her breathy little moans and the ripples of her sculpted flesh. She will not be ravaged by the waking world, or by the foolish oafs who dare try and tarnish her beauty (they are all oafs, the fairies have decided, each and everyone one of them, unworthy of their princess).
But she will not reach out to touch them, her delicate fingers spread and willing. She will not open their mouth as they ride it, giggling at the taste of their little cunts. She will not laugh as they touch each other for her amusement. She will not wail and scream their names as the three of them work busily between her legs.
None of them have ever tried to kiss her on the lips. And they have spent the last few centuries pretending that the thought of doing so never occurred to them, no matter what filthy things they inflict on the rest of her body.
They haven't, yet. But the risk is so tempting. Not to mention that inevitably, they know they will forget why they cannot risk kissing their princess, and then they will forget there was ever a rule against that at all.
They've decided to wait a little longer, to relish this perfect sleep for a little while yet. Then they will see how to best arrange their tiny mouths to stir their princess awake.
They have no doubt that it will work when the time comes. After all, what better way to break a curse than with the truest of true loves?