It was around the third week that Celestia began suspecting that the recent change to her dreams may have been the work of her sister. The shift had been gradual, which is why she had not noticed it earlier, but finding herself staring at the sweat running down her sister's alluring flank inside her own dream finally made her wonder how she'd got here.

"What's wrong, Sister?" the dream Luna asked, raising her tail higher and leaving absolutely nothing to Celestia's imagination. Her sweat wasn't the only thing that was dripping. Then Luna's clit gave an inviting wink, and Celestia found herself needing to draw in a sharp breath to not jump to her knees and slurp at it. The impulse terrified her and, working on instinct from a millennium of dreams unprotected by her sister's dreamwalking, willed herself to wake up. Within moments her surroundings shifted back to her ornately furnished bedroom, leaving her panting beneath the covers.

Before she'd even realized it, her hoof had traveled down her body towards the disconcertingly wet spot between her hindlegs, but she forced herself to stop. It wouldn't do to pleasure herself while thinking of her own sister... though thinking of anything else when the need for pleasure found her had become more and more difficult over the past weeks. Of course, that only left her constantly unsatisfied, reinforcing a vicious cycle.

"Not anymore," Celestia whispered to herself. "If Luna really is behind this... she has a lot to answer for." Grumbling, she tried to get comfortable in the luxurious bed again, finding it more difficult than such an exquisite mattress should ever allow, and hoped to catch another hour of dreamless sleep before she needed to start the sunrise.

The dreams had started off innocently enough. Celestia simply found herself spending time with her sister while she was asleep, visiting places their duties didn't leave them any time for. It was during a visit to a funfair that she'd first noticed Luna's increased presence in her dreams, but when questioned, she'd not shown any awareness of being in a dream. "Please, Sister, if anypony knew us to be in a dream, t'would be I!" she had boasted, and she hadn't remembered the conversation in later dreams either. Now Celestia suspected this to just be a deception.

Dream Luna had never worn her regalia when they were together, and neither did Celestia, preferring to leave that burden, that she bore happily in the real world, behind in a world where she was not needed to bear it. But there were other differences that had crept in over time; Luna carrying her tail higher than normal, making innocently suggestive comments, brushing her wing against Celestia's flank as they walked... and over time, Celestia's body had started responding, eventually leaving her waking up with a burning need between her hindlegs that she didn't have any time to satisfy.

The most recent few dreams, Luna had been openly offering up her body to Celestia in all but words, always ending up on her back or kneeling in front of her sister, her legs spread wide and pussy already dripping. The very thought brought back the memory of that sweet scent to Celestia's mind. Luna's words had never shown any definite indication of her desires, but her intentions had been clear - and last night, Celestia had almost given in.

There was no way all that had been the work of her own mind. Her own mind wouldn't... tease her like this. No! It wouldn't have her sister propositioning to her at all! The fact that she'd needed to correct herself like that only unnerved Celestia further as she headed towards breakfast, keeping her tail tucked low to avoid any undue attention to her state. She would end this, today.

"I know not what you speak of," Luna spoke, narrowing her eyes as she spat the words back like an accusation of her own. "My work governing the dream realm is tiring enough as it is. And my duty is to improve my subjects dreams! Why would I spend the time making your dreams upset you?"

"You practically threw yourself at me, Luna! You've been doing it every night!" Celestia objected, her voice slowly rising in shrillness as pent up feelings of anger unloaded themselves. At least, she told herself it was anger. "Dreams can go to strange places, I know, but my own suspicion can only remain at rest for so many nights of being made to stare at my sister's wet, dripping-"

"I do not need to hear this," Luna cut her off, picking a random piece of fruit off the table with her magic and stomping towards the door with as much grace as her tired form allowed. "The Night Crown has had an exhausting night. We shall retire now for the day." And before Celestia could retort, Luna had slammed the door behind herself, leaving Celestia to stew in her emotions.

These emotions remained throughout the day, leaving Celestia distracted and out of focus as she heard petitioners, opened two gardens and a school, and later in the evening when she read 13 different reports of her government departments. She barely got through the last one, feeling herself leaving a slight puddle on her chair every time her thoughts drifted to her sister. She hadn't shown herself at dinner, preferring to have one of her Night Court bring a meal to her bedroom, so no further outlet had offered itself.

Celestia actually found herself fearful of going to sleep, but with the effort she'd expended over the whole day to remain concentrated on her tasks, she knew that she couldn't possibly get through the next day without resting her head. Shakily she stepped towards her bed, shaking off her horseshoes along the way instead of placing them in the neat square she usually did, and then climbed beneath the soft covers. She was asleep within seconds.

When Celestia opened her eyes again, she realized immediately that she was in a dream, given how she found herself observing a slow sunset that was not of her own making. She smiled and breathed a sigh of relief, drawing in deep the cool evening air surrounding her balcony. For once, there was no sign of her sister, and though she felt a pang of guilt at ever seeing that as a good thing, she tried to move the thought to the back of her mind, deciding to go for a flight through her own dreamscape to help clear her head.

Before she could even spread her wings, she felt a weight upon her back, a pair of dark blue forelegs wrapping around her barrel and pinning her wings in place. Her sister's body was unmistakable, and the voice speaking the next words removed any doubt as to who had assaulted her. "Going somewhere, Sister?~"

Celestia had never heard Dream Luna use such a tone before, and her eyes widened in shock as she tried to squirm free from her sibling's shockingly powerful grip. "Luna, what are you doing?!" she yelled out, but her attempt at being commanding was undercut by her own fear of how things might proceed - or what this new, bold Luna might do if she noticed her sister's physical reaction.

"What am I doing?" Luna replied, her voice displaying a much more convincing tone of anger that scared Celestia even further. "What were YOU thinking?!" The mare was frowning furiously, and ground her hips forward, causing Celestia's forelegs to buckle and the mare to let out a shocked moan that she hoped went unnoticed.

"Whatever do you mean? I only-"

"Shouted lurid details about my advances for the entire servantry to hear? Oh, I am well aware of what you did, Sister," Luna immediately fired back. Celestia didn't like the pause that followed after that outburst, but didn't dare bring up another objection, deciding to wait instead. She regretted it immediately.

"My intent was for you to take the first step, or indicate clearly your disinterest. The latter possibility has long been disproven..." Celestia gasped as she felt Luna's magic brush against her wet lips, and had to bite her tongue to suppress a wink. A drop of her juices fell to the floor regardless, impacting with an incriminating 'plop' that was heard easily in the unnaturally quiet night of her dream. "But it seems like more drastic steps are needed."

"Luna, what are yy-aaaaAH!!" Celestia yelped in surprise as Luna flipped her over onto her back, quickly turning around and settling down on top of her, the elder sibling's eyes growing wide as she came face to face with Luna's puffy pussy lips, the scent that had caused such strong reactions within her from afar almost intoxicating up close. She felt herself winking, and groaned as she tried to somehow squirm away.

"Lun-... ghh!!" She'd attempted to grab Luna's rump and lift the other mare off her, but Luna had only smirked and let out a pleasured moan, a drop of her own arousal landing on the very tip of Celestia's muzzle. Having the scent that close to her nostrils made her moan, and she tried to close her eyes and turn away to stop herself from giving in to what was so obviously Luna's intent.

"Oh no, dear Sister... you have brought this upon yourself. If you wish to stand again... you may after you have pleased me to satisfaction!~" Once again Luna acted before Celestia could object to her words, and any of her own she might have spoken in response immediately died in a scream of pleasure as Luna's tongue buried itself in her marehood.

Luna's tongue was heaven and hell at the same time. It was the most pleasure Celestia had received back there in as long as she could remember, her sister digging in relentlessly and slurping at all her most sensitive places, no doubt having used her powers to extract from Celestia's mind exactly which spots those were, and attacking them without any buildup or mercy. Already Celestia could feel her own peak building, and she moaned openly, Luna humming in approval as she felt Celestia's warm breath against her marehood and ponut.

"Oh dear... if you cum before me, Sister, you will need to match that with another orgasm from me for every one of yours~" the night-blue mare chuckled, swishing her flagged tail invitingly. Celestia groaned and squirmed again as the realization of that threat settled in, but her impending orgasm made it difficult to think. She'd opened her eyes again, too, and Luna's glistening pussy pushed all other thoughts aside. She needed to get out of this situation, so she did the only logical thing her overwhelmed mind could settle on.

The moment her tongue made contact with her sister's lips and the sweet, lustful juices on them flooded her tastebuds, Celestia screamed, releasing an orgasm that she'd pent up for weeks and that soaked her own tail within seconds, leaving the normally flowing pastel rainbow flat against the floor. Luna withdrew her tongue immediately, letting Celestia's pussy clench down on nothing as she winked desperately for enough stimulation to carry her through a long and intense peak, but it was over before she would have liked, leaving the mare shivering beneath her younger sister and gasping for breath.

"Mmm~.. That makes two orgasms you owe me now, Sister," Luna remarked with a playful smirk, before diving right back in during her sister's afterglow and making her twist and groan below her in desperation. Fearing falling behind even further, Celestia quickly returned her muzzle to Luna's pussy, and, after only brief hesitation, she pressed her muzzle close as if to bury it inside, her tongue beginning to lick and slurp like her life depended on it.

Luna moaned happily, both in response to finally getting the sensation of her real sister's tongue eating her out and in approval of how Celestia's marehood reacted, drooling a steady supply of juices for her to slurp up while eating out her sibling. The combination of the taste of Luna's sweet juices, as well as the scent of her arousal on every breath she drew, slowly pushed all doubts and worries from Celestia's mind, her breathing calming and her slurps becoming more passionate instead of frantic as she muffled her moans into Luna's pussy. Even her grip on Luna's rump had changed to lewdly squeezing it on instinct instead of trying to escape its weight.

Luna smirked and decided to reward her sister by giving the clit in front of her a few flicks of her tongue, causing the white princess to muffle a groan again. She watched with visible amusement as Celestia's hindleg twitched and her wings attempted to unfurl against the floor of the balcony. She could feel a hesitation in her sister's slurping, almost as if she was realizing something, then moaned in pleasure as Celestia's efforts increased in their determination. Not to be outdone, the Princess of the Night refocused her concentration on her own efforts as well, muffling moans of her own as she felt herself getting closer to her first peak of this night.

It quickly became a race between siblings, Celestia with the advantage of a slightly better position to get her tongue deep inside her sister's marehood, while Luna knew exactly which spots to attack with hers, but Luna ended up being the one who lost control first, having held out since the beginning of the evening - and probably even before, or at least that's what a thought suggested that briefly crossed Celestia's mind. It didn't linger long, though, her sister's more melodic moans and the - from her perspective at least - torrential maregasm flooding her muzzle from above occupied her and made her shiver in her trapped position, desperately trying to hold on and not undo her progress to freedom by unleashing another orgasm of her own.

Still, she knew that Luna could probably keep her there as long as she wanted, and the only way to escape that would be to overwhelm her before she could concentrate enough.

Trying to ignore the feeling of Luna's pussy flexing beneath her tongue, Celestia relentlessly pursued her task even as Luna's orgasm began to subside, the younger mare groaning and fidgeting her raised wings from how sensitive she felt immediately after her peak. Then she suddenly let out a moan that exceeded all others except her orgasm in volume, and Celestia paused, processing that reaction. Then she began licking over and over at that spot, taking controlled breaths due to how deep she had to press her muzzle against Luna's folds to even reach, making her sister squirm and softly kick her legs as Celestia had discovered her g-spot. Maybe Celestia had found an advantage after all...

Her hope did not last long, as Luna had no intent of playing fair. Within moments of Celestia gaining her advantage, she felt Luna slurping at her clit again, but this time Luna did not stop, attacking it over and over and over, Celestia barely able to keep going as she was forced to muffle high-pitched moans into her sister's folds. Desperate, she decided to mirror her sister's actions, shakily extending her tongue, wrapping her lips around the nub and beginning to flick it over and over while suckling on it - and she could not have hoped for a better reaction.

Luna SCREAMED in pleasure when her clit was focused on, winking rapidly and no longer able to concentrate on giving Celestia any pleasure of her own, beyond ineffectually breathing against the older mare's folds beneath her as her loud moans quickly decreased in volume - not because she was calming, but because she simply no longer had the breath to sustain them. Her hooves curled and tried to grip the balcony floor, and her hips instinctively ground backwards, causing muffled huffs from her sister as her muzzle was scrunched by the motion. If Luna registered it, it wasn't noticeable; her eyes had grown unfocused and her tongue was hanging out of her mouth, a drop of her saliva hanging precariously on the end.

When Luna came this time, she practically exploded. Had someone been listening and nothing else, they would not have judged it this way, the princess's voice exhausted and quiet compared to when she had cum the first time, but her body rocked and shook, and while Celestia had been able to gulp down most of Luna's previous maregasm, this one soaked most of the fur on her muzzle and the rest of her face.

It lasted longer as well, and when Luna finally raised herself off Celestia's face, her legs quivering with the effort after such an intense peak, Celestia wasn't really sure how long it had been. She also felt an odd pang that it was over, and while she initially tried to attribute it to her loins crying out due to not having been able to find relief for a second time, she stopped her mind from dismissing it so easily and examined the feeling more closely. No, she'd actually wanted this to continue. But why?

As Luna stretched and got to her hooves, Celestia furrowed her brows in thought, trying to make sense of her own feelings. She was certain that a bit of sex hadn't fundamentally changed how she felt about her sister... so what was it? She closed her eyes, and let the events and the feelings that accompanied them replay in her mind. She and her sister, united in utter bliss, more intimately than she'd ever managed before. No worries, no barriers. Just giving each other pleasure, and pushing each other to do so even more. She shivered, both from the fresh memory and from the realization.

"Are you.. alright, Sister?" Luna asked, much more timid now than she had been before. Having her need satisfied seemed to have calmed her, and now sisterly concern had returned to the forefront of her tone of voice.

Celestia remained there on the balcony floor and pondered the question for a few more moments. "I think I am, Luna," she finally replied. The words felt right as she spoke them, so she nodded for emphasis, opening her eyes and meeting Luna's gaze. The sight of her younger sister made her smile, shoving her lingering doubts to the side. "I look forward to seeing you tomorrow night."

Luna's grin had never been wider.

Author's Note

If you liked what you read, I'd be very happy about an upvote, and regardless: thank you for reading!~