Celestia’s screams of ecstasy fuel my own, and help bring my fourth climax of the night. I lick my lips while I watch them kiss, and revel in the pleasurable aftershocks of my sexual high. I bite my lip to stifle a moan which would undoubtedly give away my presence and quickly wipe away the majority of my ejaculate with a foreleg. It feels sticky and not entirely pleasant when stuck to my coat, but it’s preferable to having my sister and her student— her lover find out that their lovemaking wasn’t exactly... private.

I’m still having a hard time wrapping my head around the fact that my sister and Twilight were involved romantically. Actually, no. From the moment I returned, I could feel that there was a certain... attraction between them. I just cannot believe that they managed to keep it a secret for so long. Especially from me! And this after I ranted to Twilight about the lost art of subtlety... Perhaps I shouldn’t have snuck into Celestia’s room after her...

My cheeks flush and my breathing quickens once more when I think about what I’ve seen. The truth of the matter is that I should have left them to their own devices when they started talking about lovemaking. I should have fled the room and gone back to my own. The mental images alone would have been more than enough to ‘do the deed’. But between my sister’s experience and Twilight’s incredible magical attunement, they would certainly have noticed had I tried to slip past the barriers.

My vaginal lips clench, winking against the air and make a liar out of me. Okay. Okay. I could probably have slipped past their magical defenses without detection. Especially considering that they are turned to the outside, and their casters weren't exactly paying attention. It is never as hard getting out as it is getting in. The knowledge that they don’t know of my voyeurism, however, brings me such an illicit thrill! To say nothing of the act of watching them itself.

They truly are beautiful together, and I’ve already found myself wishing I was in either of their places more than once. I dare say I’m envious.

I swallow to lubricate my dry throat and chance another look into the bathroom. Half a glance is enough to make me pull back behind the relative safety of the wall, and scramble for my concealment magic; they’re coming out.

Will this be the end of the evening’s festivities? My horn still tingles with the high-yield magic that Twilight flooded the entire room with, and I can’t help but wonder how either of them have any stamina left at all.

With a wave of my horn, I pull at the shadows that surround me, and wrap them around myself once more. It takes me another moment to bend the shadows around myself just so in a way that allows me to see from my cocoon of malleable darkness, just in time to watch Twilight magick my sister over to the bed and crawl on there with her.

To my surprise, Twilight doesn’t curl up against Celestia like I would have expected her to, but instead lowers herself in preparation of more intimacy. My tail thrashes inside the cocoon and I can hardly suppress a squeal of excitement.

Twilight’s words when she looks up from between Celestia’s legs, quickly put a damper on that excitement. “Don’t you have court in a few hours?”

Please say that you won’t go, Celestia. Just forget about your duties for— “Fuck court.”

“Huzzah!” It isn’t until a few seconds after both of them stop moving that I realise that I might have actually whispered that aloud. Whether I did or not appears to be immaterial as they apparently wish to continue with their steamy lovemaking. My imagination helpfully conjures a very vivid scene showing Celestia doing exactly that. Countless mares and stallions satisfy her sexual needs, and she them in turn. Although for some reason, Twilight is there, too, doing all of those things together with Celestia for whatever reason. Perhaps I cannot picture them being apart?

The wet squelches signifying sex resume, as do my sister’s passionate moans, and I am quickly pulled back to the debauchery taking place in front of me.

Emboldened by the fact that even my involuntary vocalization hasn’t tipped them off to my presence, magical or otherwise, I cautiously approach the bed. Slowly, lest I break the tenuous spell keeping me hidden, I move up to the edge, my eyes glued to my sister’s dripping sex and Twilight’s muzzle which is all but buried within it.

I shouldn’t. It’s dangerous. But watching them turns me on so much that I can’t help myself. Licking my lips, I lower one of my hooves to my own sex, slowly rubbing myself while I watch, mesmerised.

Twilight is bolder towards my sister than I would ever have thought her capable of being. She licks, and kisses, and teases like she was born to it. At one moment she is lavishing Celestia's clitoris in a tongue bath. The next, her magic spreads my sister's labia wide enough that I can see her insides ripple, fighting a desperate battle with the magic, trying to coax virile sperm out of a facsimile of an object which doesn't possess any.

Or does it?

“Oh, Twilight... Fuck yes!” As Celestia’s voice reaches a crescendo, Twilight’s magic pulses inside her and grows in strength. At least, that's what it looks like at first. From the surprised whinny that Celestia lets out while her body writhes against the sheets, and the magic that begins oozing around the cylinder after only a few pulses, I realise that Twilight must have found a way to replicate the experience. Although listening to my sister gives the impression that Twilight’s magical cylinder is pumping her full of liquid pleasure.

"Oh my stars, Twilight! Fuck... don't stop!"

Celestia cries, and the viscous magic streaming from her gaping sex, easily carrying me to another peak. My body shudders and the metalic taste of blood fills my mouth when I bite my lip to keep myself from moaning aloud. I know one thing for certain: I want to know what it feels like.

Finally, after seems like an age, Twilight shuts off her magic. Her legs wobble for a moment and I am amazed that either of them still has the stamina to do... well... anything. She takes a moment to steady herself and then crawls up Celestia's body until they are muzzle to muzzle. Down below, I can see Twilight's renewed excitement, and Celestia's labia, still gaping slightly after the workout she just received.

I want to taste it. The thought catches me by surprise, and I shake my head to rid myself of it. Of all the ludicrous, irresponsible ideas, my mind has to come up with the one that will surely get me found out. And yet, I find myself already halfway there. My own nethers are urging me to go straight for the source, and my mind doesn't seem to be inclined to disagree.

With a surge of willpower, I pull myself back from the utmost edge. Close enough that I can smell their sweat, and fluids. It doesn't matter. All of it turns me on like nothing I've ever felt, and I quietly sneak back to the side of the bed.

"Did you like that, Princess?" Twilight asks her exhausted lover. I can't quite put my hoof on it, but something in her intonation is... different. More sultry perhaps? Celestia's response is too soft for me to make out, but Twilight smiles and kisses her softly. Of course, that makes me wonder what it would be like to feel her lips on my own, possibly while Celestia's make nice with my other set of lips...

My excitement sends another few droplets running down the rivulets on my leg, and I can't quite stifle the moan that comes to me at the thought of something so hot. Fortunately, their exhaustion is such that neither notices the sound, and for the second time tonight I skirt the edges of getting caught due to sheer luck. The thought of sneaking in between them and stealing a kiss or two flits through my mind. By now, they seem so out of it that I might be able to do just that, but I’ll have to hurry before they engage one another in another minutes long make-out session. Moving quickly, I circle the bed and climb on close to them. I lean in, pursing my lips, before something makes me stop.

Wouldn’t it be much better if they knew you were here? A small voice in my head asks, and I find myself agreeing. All of this sneaking around and watching them rut each other's brains out is a treat, but being able to join whenever I wished would be much more wonderful. I should stay my hooves for now. If they were to discover that I was here, there’s a good chance that everything would fall apart.

With a nod to myself that nopony else can see, I pull back, scooching over to the edge of the bed and making for the door, resisting the impulse to continue watching them. Once I’ve left the bed, my movements become much faster. A simple dampening spell to quell the noise and I am all but sprinting for the door, diving into a cloud of stardust which lets me slip through the cracks with ease. After that, my own room isn’t too far off.

After materializing in my own room, I head for my desk and pick up a stack of papers that has gone unused for a long time. Picking up a quill, I begin scribbling down ideas, thoughts, and actions that could possibly help me achieve my goal.

What I really need to do is observe them. Learn what they like, and dislike. Their most sensitive spots, and what it is that excites them. I smile to myself and lick my lips. I’ll have to make sure to observe them very, very closely. Whenever Twilight is at the castle, I should try and make sure that I’m present for any of their future... encounters. I can feel myself wink against the cold, marble floor. I’m making a puddle again.

And after I know all I that I’ll need. I have to be able to gauge their reaction to my presence in a safe environment. A smile plays around my lips when the solution presents itself: My dream realm. If I am cautious, I should be able to draw up a dream like that for both of them.

It’s good to be the Princess of the Night.

Author's Notes:

Alternate Title for this chapter: Enigmatic Princess