The story
Luna's moon had passed it's zenith across the sky and the ponies of Ponyville slept peacefully knowing that the day was safe once more. Not only that but, the Crystal Empire was now safe and would be accepting Tourists for the second day of the Crystal Fair. Only one building had any waking occupants. The Golden Oaks library home to the Sister-In-Law of the Princesses Celestia and Luna. Not to mention the personal protege of the Solar Princess herself, Twilight Sparkle. She was awake attempting an all night study session as was her usual routine. But, this time something was different.
This time she had decided to pursue not the subject of Magic but, something much more personal. She had recalled a comment her number one assistant and best friend Spike had said a long time ago after the great dragon migration fiasco. "You're Not My Mother!" The anger that he said those words with still resounded in her heart. But, she didn't know why.
"Ohhh... This is so frustrating. None of my books can tell me anything on the subject. Even Princess Celestia didn't know what to do." She said with an exasperated sigh as she placed her head on the desk she was using. She had known Spike since she had hatched him. But, until recently she had only considered him a best friend or at best a little brother. But, during their adventure in the Crystal Empire when she saw Spike's reaction to his dark magic infused nightmare something clicked. She felt saddened that he would fear her sending him away. But, when she promised to never do anything of the sort her heart nearly burst with emotion as he hugged her.
That was nothing compared to the emotion she felt as she watched him save the Crystal Empire with the help of Princess Cadance. She was scared for his safety as he fell. She almost couldn't bear to watch but, when Cadance rescued him she was on the verge of joyful tears. "Why can't I place this feeling?" She said softly as she decided to go to bed. As she blew out the candle on the desk and lit her horn with an illumination spell she noticed something. A book she had left on the desk had fallen and opened to a different page.
Curious as to what was written on the page she decided to read. What was upon the page fit her feelings completely and when she checked the cover she had realized that she had dismissed the book on a hunch that it would not contain the answer. She chuckled inwardly as she recalled the fabled Poison Joke incident where she had done the exact same thing. "Well, I guess old habits die hard." She says with a happy sigh as she placed the book on the desk and headed upstairs to get some sleep. But, when she got upstairs she found that Spike was having another nightmare.
"N-No Twilight, please don't send me away... I-I promise that I won't break anything else... Please!" He cried out in his sleep the baby Phoenix Peewee sat worriedly beside it's master. It was then that Twilight had an idea. She levitated Spike over to her bed and snuggled him next to her.
"It's okay Spike. I'm here. I won't ever leave you. I promise." She said as she kissed the young drake on the forehead just below the crest. She had remembered that her own mother had done this for her when she was having a nightmare. Even if it was only a faint memory. But, it had the same affect, Spike calmed down almost instantly. But, before drifting off to sleep again he said something.
"I love you mommy." It was quiet but, it still brought proud tears to Twilight's eyes. Her question from earlier had been answered. She knew now exactly how she felt about Spike. She was more than his elder sister, she was his mother. Perhaps not by blood but, definitely by action she had proven it. As she kissed his forehead again she whispered.
"I love you too Son." She said with a smile before sleep claimed her as well.
Dear Princess Celestia,
It has taken me a long while to finally sort out my feelings about the young drake in my charge.
But last night when I had helped him through a nightmare the way my mother did something clicked.
So I hope it pleases you to know, that I have begun to file all the formal papers to make Spike Nathanial Sparkle my legally adopted Son. Wow that word will take some getting used too.
I have realized that the bond I had with Spike was much different from the bond of a sibling like I have with my brother Shining Armor.
I found it was much closer to the bond I had with my Parents except I was on the side of the caregiver.
I have come to realize that it's not blood that makes a parent. But, the desire to do what's best for your child. I wouldn't give up Spike for anything.
I'm sorry to say but, that even includes you Princess. Thank you for letting me raise him and in the process making me the luckiest mother in Equestrian history.
Your Faithful Student and Spike's new Mother, Twilight Sparkle.
P.S. What really settled it was him saying "I love you Mommy." When I comforted him.
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Celestia smiled as she read the letter that she had received via the mail that morning. "I'm proud of you my faithful student. I know you'll continue to raise your son well. Just like you always have." She says as she looks towards a shaded stained glass window that seemed to brighten. It's image conveyed a lavender unicorn astride a mighty purple dragon that breathed green flames. Upon the bottom of the glass there was an engraving written in the language of the dragons that had given Spike's egg to Celestia. "ekess hesi deevdru achuak ibafarshan yth fehlim nomeno lorsvek svadrav wux yor wer itov di wer dask ti dout kurjh nishka dout thatheo xkhat stejar" Which translated too... "To our son green flame we grant this prophecy when you learn the love of the mother not your own shall your destiny become visible."
"Good luck my little ponies." Celestia said with a smile as the credits began to roll.