It was nearly midnight when Princess Luna heard the first cry emit from upstairs. Luna was in the cozy downstairs library, in the castle the two princesses shared as a home. It was just one of her favorite places to spend her night off, the night of the new moon. The one night every month the moon did not grace Equestria’s beautiful night sky. She was reading down here where the sisters stored the copies of their favorite books.

Luna wasn't even sure that the first cry she heard was real. She was - for starters - reading one of her favorite horror novels and this would not be the first time she had gotten lost in the book.
“AAAH!!!” The second cry rang out through the castle (or at least a few floors of it). Luna was entirely puzzled, as that was surely not any shriek of pain nor distress she had ever heard before, but what else could it possibly be? She did know one thing from hearing that second sound. It had come from her dear older sister, Princess Celestia!

Luna, acting as any good sister would, knew she should go upstairs and see what all the trouble was. She quickly noted the page she was up to, placed the book on the table and rushed upstairs. When she reached the top of the stairs to the third floor she sighted her sister’s room. The light was still on. Surely her sister would be asleep by now?
“ohh …mmm.” Okay these were definitely not moans of pain or distress. But what the hell were they? Luna paused outside her older sister’s bedroom door. Maybe everything was fine. However the noises she had heard were certainly not normal sounds! Luna gathered her resolve and opened the door. Then immediately wished she hadn't! All she could bring herself to do was continue to stand there awkwardly as her sister noticed her presence and turned her head toward her. Luna could not believe her eyes! Her graceful and highly respected sister was lying on her bed, legs spread wide apart with her bare hoof between her thighs! As a few seconds passed Celestia’s hoof came to a stop and a look of embarrassment slowly took hold of both of the mare’s faces. Celestia’s face moved to puzzlement as she asked,
“Luna?” As if she wasn't sure if it was her own sister standing in the door of her room. Luna’s face remained just as embarrassed though it did get redder with every passing second. Luna honestly did not know what she was witnessing but she knew it was definitely private!

“S-Sorry.” Luna stammered, stepped back and slammed the door shut with her magic. All Luna knew now was that her sister was doing something very…well, sexual and knew it was something she should not have seen. Though there wasn't a stallion of any description is sight, she just somehow knew the nature of her sister’s actions. Filled with embarrassment she dashed away, jumped out the nearby open window and spent the rest of her night trying to forget and trying to figure out what she had just seen, as she flew across Canterlot’s beautiful starlit night skies.

Twilight Sparkle was doing something that had to happen just too often in the Library in Ponyville, cleaning up. However it wasn't because it was really needed. Her good friend Rainbow Dash was going to arrive at the library any minute now to read the new Daring Do novel that had come out just this morning. Actually it probably didn't make much sense cleaning up before Dash came over. For one Dash probably wouldn't notice and two she usually was the cause of a fair mess with her ‘awesome’ entrances.

Suddenly Spike stopped assisting her clean and bent over, then as happens, released a jet of green fire into the air above their heads. Surely enough a letter from Princess Celestia had arrived. The question was why? Twilight hadn't sent a letter in a few days and was certainty not expecting any kind of response or letter of any kind. Twilight plucked the scroll out of the air with her magic and brought it around so she could read it. She immediately noticed that the scroll had a note attached to the outside of it, which was not a common thing for the princess to do. She pulled off the note and read the hastily written text.

Read in 100% Private, no Spike

Okay now Twilight was suspicious. However she must follow all of the Princess’ instructions, and there would surely be a good reason for the privacy policy.
“Spike, I’m going to have to read this up in my room.” She told the baby dragon, “Finish up here, Rainbow will be here any minute.”
“Aw come on, why can’t you just read it here?”
“Princess’ orders,” Twilight replied and trotted up the stairs. It wasn't everyday she got an impromptu letter from the Princess!

Once Twilight had taken a seat at her desk she opened up the letter.

To my faithful student Twilight Sparkle,
I am fully aware that it is your assignment to report to me about your friends and possible issues you may have had or are having with them. However I must come to you for advice as you know I appreciate your insight and couldn't think of anybody else I could ask. I need advice as to what to do in a certain situation.

To sum it up there was an incident with Luna last night. I had forgotten that she was home because of the new moon last night and she found me doing something that may have upset her. It was quite embarrassing for the both of us and I’m not quite sure what to tell her. Hmm… yes that’s all for now I believe.

-Princess Celestia

Twilight was quite confused. How was she supposed to give advice to the princess if she didn't have any idea what had actually happened? Well she had to reply right away as she was sure it was a very important issue to have both of the Princesses involved.

Dear Princess Celestia,
I apologize in advance for not having much advice to give. To be straight I didn't have too much to go on in regard to the nature of the incident.

The best advice I can give you is to talk to her about it. Almost every problem can be resolved by discussing your issues with each other. I am sure you had a good reason for what you were doing and could explain yourself to Princess Luna quite well.

Always your faithful student, and occasional adviser,

Twilight Sparkle.

Celestia was honestly quite disappointed with Twilight's response. She had expected, or more accurately hoped, to receive some advice that would help her avoid that certain explanation to her sister. She did accept that the letter was addressing something that Twilight didn't know anything about what had really happened. That was Celestia’s own fault and she realized that she would have to just go and talk with her sister.

It didn't take long for her to spot Luna. Her dark coat stood out clearly against the morning light. Celestia, as casually as possible, pulled up next to her sister.
“Luna, what are you doing out here? I thought you were going to stay home tonight, and well this morning.”
“Well I was, but then I saw you… you know…” Luna trailed off awkwardly.
“Oh, right. That,” Celestia responded to Luna’s awkward comment as best she could but couldn't seem to get herself to find a way to best explain herself. She figured she’d try to start off with reasoning. “Luna a lot has changed in the 1000 years you've been gone. I’m sure you've noticed this in basic daily life. I believe it is my duty to explain to you the changes that have become apparent in the,” Celestia paused, “more private parts of ponies’ lives today.” Celestia proceeded to tell her sister about what she was doing and how it had become common among everyday ponies and that it was usually a private activity and was very embarrassed about the incident earlier that night.
“THAT’S,” Luna stopped herself. She was going to say disgusting but that wasn't what she truly thought at all. She was quite enticed by this idea of a formally unknown pleasure. Her sister had been honest with her and it was Luna’s turn. “Well I suppose it does sound kind of appealing.” Luna said as a blush crossed her dark cheeks. The look of relief on Celestia’s face was almost comical. She had been so sure her proper sister would have been utterly disgusted and hate her.
“Celestia?” Luna attempted to get her sister’s attention again.
“Yes?”

“Um, well I would like to try this sort of new activity but I don’t really know what I’m doing. I know you said it’s a really private thing but…would you teach me?”

For the second time that day an unexpected burst of green flame blew over Twilight’s head. Twilight was lounging on the couch with Rainbow, who had arrived quite immediately after she had sent her earlier letter to Celestia, when it scorched their manes.
“Spike!” Rainbow complained, “What would have happened if you had burnt the book!”
“Sorry,” The young dragon responded. “I’m leaving now anyway; Rarity said she wanted some help at her shop today.”
Twilight was less concerned with the concept of Spikes departure or her books being destroyed – that was a first – and more concerned about the fact that she had received another letter form the princess. Even more concerning was the note attached to this letter.

URGENT! 100% Confidential

It was obvious that Twilight had to read this letter immediately but she really didn't want to move from her spot on the couch with Dash. Prioritize, Twilight told herself.
“Sorry Dash, urgent letter from Celestia” Twilight said as she made her way from the couch to the bedroom staircase.
“Cool,” Rainbow was clearly reabsorbed in her book.

Twilight,
I need to skip the formalities and get straight to the point I desperately need more advice. First thing you should know is that I explained to Luna about the incident that happened last night. However now she wants me to teach her how to… well you know. Actually I didn't tell you what actually happened Last night did I?

As Twilight read on about the incident she was firstly shocked, then confused, and then shocked again. Twilight would never have guessed that the princess would ever partake in any such things. What shocked her most were the last few lines of the letter.

So what should I do? I know Luna wants a quite hooves-on lesson and I don’t know if it is something that I should agree to or disagree to. Honestly I do find the idea quite exciting. Being a young pony of this generation what would you recommend?

-Celestia

Twilight didn't quite know what to say. She herself really didn't know much about that area of life. Maybe it would be something she should know. Who could she ask though? She was so afraid that maybe a request like this might make her friends think she was weird. Then Twilight realized that the one pony she really wanted to ask to give her a hooves-on lesson was sitting on her couch, all alone.

Author's Note

Hey people this is my first ever fic so be kind to me. I’ve tried to setup this story quite well here and if it gets a good response I should be able to write/post a second chapter. The only thing else I wanted to say was that even I’m not quite sure when this story is set. It could really fit anywhere before the last episode of season 3 (which I haven’t actually seen yet) and after Rainbow discovers Daring Do. Finally I don’t know what the title really means it’s kind of just like a pun on the word sisterhood and ‘hoof’ which is a key part in ‘the incident’.
That’s all, thanks for reading, hope you enjoy, please like - or dislike if you must :’( - and give me feedback (all edited and written myself so I expect there to be a few errors) in the comments.
Until next chapter I suppose.
-LupusLuna