//------------------------------//
// Old Friends Are The Best 
// Story: New Moon 
// by MistyShineStar 
//------------------------------//

      Celestia's eyes grew very small. She levitated her tea over to her quickly, surprised by the question. She took a long sip.
After the long drink, she said, "Well, um, you see, Luna, uh... Let's change the subject, shall we?"
"Sister, I am not dumb. I can tell you are stalling, and I wish to know the truth. I am a grown mare, it isn't like you are trying to give a filly  'The Talk'."
Celestia closed her eyes, and put her cup down on the dresser next to her with a sigh. "I guess you are right, Luna," she whispered. "It is time you know the truth."
"Little sister, I know that I should have told you this a long time ago, but...." Celestia's eyes were clouded with pain, the same kind Luna saw before she had banished her. "Not everypony lives forever."
Luna felt as if she had been punched in the stomach. "But....dear sister....this can't be possible...."
Celestia turned her head away and said, "LuLu, it is. I know what the pain is like, not being able to make many friends. I have to avoid doing so myself, as they all...." Celestia started bawling after the last word. 
Even if Luna knew Celestia was in no state to answer such a question, she couldn't help but ask. "Tia... if you can't make many friends, then why did you bring yourself to be friends with Twilight?"
Celestia mustered up a small, watery smile and said, "Well, I knew that she would be an alicorn one day, ever since she came to my School of Magic. I was able to be friends with her."
The younger sibling smiled a bit at the thought too. "Yes, I knew she would become an alicorn as well, but I didn't make a big deal of it since I thought ponies could live forever anyway."
There was a long silence before Luna spoke again.
"Tia, when do you think we will have to tell Twilight about all of this?"
"I honestly don't know. We will have to see if she already knows or not. If she doesn't, then, well, we can go ahead and tell her when she's an alicorn. I know she won't like it, but it has to be done."
Luna sighed. "We might as well," she said, sipping her own tea.
Another silence.
"Tia?"
"Yes?"
"Can I sleep with you tonight?"
Bittersweet memories of when she slept in Luna's room when she had nightmares filled Celestia's head.
"Of course you can."
The two mares flopped onto Celestia's bed, already half asleep.
"I love you, Tia."
"I love you too."