Several hours had passed in a sort of papery haze, books being quickly read, discussed, dissected, and discarded. Celestia was... Twilight couldn't really describe it. She'd often thought about the traits of an ideal study partner, but she never thought she would actually find such a perfect pony. And yet it turns out her mentor fit the ideal to a T, being just as voracious as Twilight, equally as incisive, and twice as quick to comprehend. Working as a pair, they managed to slam together a new theoretical kind of partial teleportation and sending that could lead to... Well, alright, they had no idea what it might lead to, but that was half the fun!

However, right as she put the finishing stroke on her latest note (a teleportation spell modified to only send your image), Twilight heard a bit of a rumbling, and realized that she hadn't eaten since the (admittedly nice) breakfast Spike made for her. She looked towards Celestia, who smiled, only to be caught by surprise due to her own stomach's complaint. They burst out laughing, leaned on each other, and packed up their notes. Today was her first time studying with Celestia, but even when they had been purely mentor and student, as opposed to researching together, they had a regular practice.

Celestia turned towards her and nodded.
"Lunch break?"

Twilight smiled and (gently) dropped her books onto the desk they had been working at.
"Lunch break."

Twilight had learned over the years that it was much easier to head out into the town and get meals on their own time, compared to dealing with the castle cooks. Certainly, they were all wonderful and skilled ponies, masters of their craft. But... They had certain expectations, both of royalty and royalty's students, and sometimes you just really need some donuts, and quickly. So they broke out into the fresh air of the courtyard, having a conversation whose contents didn't matter, even to them. It was just nice to decompress the brain after such a long study session.

Lunch at Pony Joe's was pleasant, even if some of the patrons were surprised to see Celestia in the building, and then downright dumbstruck to see her pleasantly chatting about ‘thaumic resonance’ or something of the sort with a mare easily one percent her age. But Twilight didn't mind, and Celestia definitely did not. They were simply comfortable again, in each other's company. It had been, they both agreed, far too long. And apparently, that gave Celestia an idea, for she quickly turned towards Twilight, eyes shining with an unfamiliar expression:
"Twilight, I had something we might want to do before we go back..."

She looked up from her fifth cruller, wiping away a crumb absent-mindedly, already back into her old student habits.
"Yes, Pr... Celestia?"

"Well, there is apparently a shop near here that my sister has just been raving about, and I figured it would do us good on our break to take a look."

"Oh, you don't say?"

Her teacher / study partner / mentor smiled at her, the grin faintly... unsettling.
"Yes- She said that she encountered Fluttershy there, who had been visiting on your suggestion."

Twilight was positive that if she could see her own face, it would be paler than Celestia's coat.
"...Oh. You... don't... say..."

--------

A bit over two hours later, Luna left the humble (and rather nice) abode of the two mares, a fairly large box in one saddlebag. She hadn't ever considered the kind of creation that Bon-Bon had shown her, but in the end, it really did seem wonderful. In... In the past, she remembered similar dishes and confections, made with delicate care to be the centerpieces of entire feasts. To see that such arts and practices still lived on, as it always did, made her smile wide and her pace quicken. She had a reputation to maintain and / or rebuild, and having a pleasant and shining demeanor seemed to help.

So she walked, and thought. It had been a few days since her last encounter with Dear Fluttershy (a nickname which had stuck with both alarming speed and surprising strength), and she had spent a fair bit of that time, in the back of her head, parsing the events. So much had been lost in the transition from Nightmare to the Banished Princess to the Nightmare and back to herself-- She still remembered, with a sort of wistful regret, how strange her first visit to Ponyville had been. It was preposterous: She had honestly, legitimately forgotten what fun was. Simply disgraceful. But one of the most painful things she had lost was her... grasp, she supposed, on normalcy and reality.

That anchor was found again on Nightmare Night, in the form of a kind and honest and loyal group of friends, generous with their laughter, and brimming with the magic of friendship. They helped her re-acclimate to the world, especially the one who, at first glance, did so very little. But however she did it, Dear Fluttershy had brought her voice down into registers that did not crack stone, brought her behavior back in line with what was required of her. Certainly, she did not mean to do such- She had clearly been scared, horribly so. Intentions, of course, don't change the results, and no matter what, if anything, she had meant to do, she had done quite a lot.

Luna would not admit it to Celestia (barring some variety of torture or possibly a tickle fight), but she felt quite fond of the pegasus mare. Was it emotional, or purely physical? That, she could not even answer herself yet- She had always had difficulty separating the two, and her 'absence' likely ruined what little insight on the issue she once possessed. Then again, such insight wasn't always necessary- Love could bloom quite nicely without physical action, and physical action, to put it delicately, did not somehow pre-require love. So regardless of what her feelings actually were, she was content to find out slowly, over time... Or right away, tonight.

Either one really. After all, she was the Princess of the Night, and night was tailor-made for surprises... Amongst other things.

--------

Twilight believed that she now had an inkling of a spot of a tiny, bare, unspeakably small taste of how Fluttershy must have felt when Luna discovered 'the shop'. And she didn't want that feeling to last much longer, because she might well die of it-- Her nerves were twinging, her eyes twitching, ears flopping, her body far far too warm, and her stomach managing an incredibly athletic series of pirouettes off of itself. Celestia, however, didn't seem to notice her immense discomfort, instead happily walking down the city streets, en route to the store where Twilight would be so embarrassed and mortified and ashamed that she would explode.
"Princess-"

Her mentor shook her head
"Twilight. I told you- At times like this, there is no need for titles between us. Celestia, please."

"Alright. Celestia please don't take me to that store."

The Princess burst out laughing at that, stopping for just a moment... And then resuming her full-tilt pace towards the shop of Twilight's horrors.
"Oh Twilight! I didn't expect a joke from you. But in all seriousness, if my sister is right, this is precisely the kind of store that I would enjoy."

"Look, P- Celestia, I don't think that this sho... Wait what?"
She broke off mid-sentence and stared at the alicorn mare, who just smiled again.

"Well of course. Twilight, as my most faithful student you know how old I am, and my life cannot be solely 'proper' behavior and courtly life. I've been around that particular block of life more times than you could count."

"...I can count to some very high numbers."

"I know."

And with that, neither of them said another word until they arrived, although Twilight's mind was full of... Well, things that we won't be discussing right now, for decency's sake. Let's just say her blush had an entirely new reason for being.

--------

When she answered the door, Fluttershy hadn't expected it to be anypony but Luna. And she was right- Luna, standing before her with a (nervous?) smile and a rather fetching saddlebag. She grounded herself, took a deep breath, and smiled.
"Hello!"
She had actually managed to say it without having any of her little moments, or even stuttering! And Luna was smiling back at her, and stretching out a forehoof to shake... Or so she thought, but it quickly became an embrace, and she stiffened, her face buried in the Princess' mane.

"Dear Fluttershy! We are quite glad to see thee- We had... A request, actually, before We come in."

"Oh! I... yes, please, go ahead."

Luna backed away and scuffed her hoof on the ground, resembling Fluttershy herself for a moment.
"Could We... That is to say, is there any way We could impose upon thy hospitality? We have neglected to locate a place to stay during our visit, and We... Feel closest to thee, out of all our new friends."

What. What. Was she really... Oh dear. Oh dear, oh dear, oh very much dear. She absolutely couldn't. She had no self-control, she slept like a slob of a pony, she...
"Of course, Luna! I would never turn you away."
...was already saying yes. Of course. Because today of all days her mouth had to decide to rush ahead of the rest of her. She wasn't entirely sure if she'd be able to make it through an entire weekend without any issues or little 'moments'... But in for a bit, in for the whole pouch...
"And... I feel close to you too. If, you know, that's not too forward of me to say."

And at that, Luna went from apprehensive and worried to bright and joyous, eyes shining. Fluttershy almost never seen anypony change their expression that fast, but somehow that suited Luna. Mercurial was the word that came to her mind.

"Thank thee! We... I am very grateful, and hopefully will not impose too much."

"Oh, I don't think you could impose on me at all."

Certainly, that was not a sentence that could be take too far out of context... She hoped. She really, really hoped. Come to think of it, maybe she wanted... No, no. That would be completely unlike her... Actually, maybe she really did want Luna to mis-interpret that. Ah- Not being able to make up her mind. That was like her. Setting her worries aside, she welcomed the Princess into her home.

--------

Much to her surprise (something she rarely experienced), Celestia found that the shop did, in fact, exist. There had been a time when she presumed her sister had simply made up the story- After all, it was somewhat preposterous. Twilight, in a sex shop? And suggesting it to Fluttershy of all ponies? The idea, on the surface, was ludicrous. But the exacting description was quite correct-- Black, small, unassuming, unlabelled, unmarked, and without any windows. Certainly a private place of business, and if she read the spells right (and she always did) they were properly tagged and licensed as a Night Shop- Private operation, discreet services, policed by her sister's half of the government. And yet she had never once heard of the place, or the owners. Stranger and stranger- Not that she minded strange. It was such a rarity (Hah!) to find something that qualified as an oddity to her after a life as long as the one she lived.

Even stranger still was the reaction of her student-- Calm, composed, eyes shut... No, wait, that isn't strange. It's just the resignation of somepony facing their doom. Well, bother- She had honestly expected Twilight to understand that all of this ribbing was in good fun. Although, to be entirely honest, she was... curious about Twilight's development. The mare had been like a daughter to her, the closest thing she could have to an apprentice without planning on giving up her station- For apprentices, by nature, one day become masters in their own right. And it was the natural response of any mentor to be curious about their apprentice, any mother to be interested in her daughter. This in no way justified the (rare) rumors amongst the court that Celestia of the Sun had a predilection for younger ponies- Although older ponies would certainly be impossible, in reference to herself.

Setting those rumors aside for a time, Celestia decided to try and assuage her student's fear.
"Twilight..."
Before she could finish, however, she was interrupted by a chuckle from the unicorn beside her.

"Oh Princess, I don't... I don't even know why I was so worried. I mean, you've seen all kinds of ridiculous things before, right? Especially related to me- You saw all my magical accidents when I was training, you were there when I first tried to fix a damaged book by hoof... Nothing could really surpass all those 'growing up' moments, right? There's no way I could embarrass myself more than I did then. So I guess I was just nervous for... nervousness' sake. Just because it seemed like something to be nervous about."

It was very likely that her student's little spiel had been meant to convince herself just as much as it was Celestia... Which is why she didn't mind. It was true: She would never think any less or differently of Twilight just because of something like this. That road had been travelled before, in the past, and she was under no illusions of it being anything but folly- Everypony is who they are, and if it brings no harm to others, then their choices are their own. Attempting to subject one's own personal rules onto a broad population... Rarely ended well. But even more important than the moral implications was the simple fact that she missed Twilight. They rarely spent time together, and what little of it they had was taken up with hogwash like the Gala. This would be different-- This weekend, these advanced lessons. She would make sure to enjoy herself, and to bring Twilight joy as well.

"Very well said, my pupil- I think you've discovered a rather important lesson just now. But you have forgotten one thing."

Twilight looked worried for a moment.
"What was that, Princess?"

She grinned, lips rising into a massive smirk the likes of which she rarely ever showed.
"Just because you were nervous over nothing doesn't mean you were wrong to be worried."

She stepped into the door, and waited for her prize student to put two and two together. Celestia had to exert strict self-control to not laugh out loud when the gasp of horrified realization came. After all, just because Twilight could not be embarrassed over her own behavior did not mean she was free from being embarrassed by Celestia's.

And Celestia had not cut loose in quite some time.