The tension in the throne room was so tangible that Luna almost turned around and walked out. No, she told herself. You are a princess, too, Luna. You and your sister are equals, contrary to what some ponies might think. Where is your dignity? Confront her like the powerful ruler that you are. Luna raised her chin, relaxed her shoulders, and strode regally to her throne.
“Why have you requested this private meeting, Luna?” Celestia asked, her voice edged with frustration. “Could it concern the complaints I have heard from hundreds of ponies about your two-week absence from night court? Maybe you would like to discuss the nightmares that have recently plagued millions of ponies, myself included? Or, might you care to explain why you have slacked off on your most important duty—hmm, I forgot what it’s called, oh, yes—RAISING AND LOWERING THE MOON?!” Celestia’s Royal Canterlot Voice shook the foundations of the castle. The crystal chandeliers above them tinkled lightly as the ground trembled. Luna, however, remained unfazed, locking eyes with her sister.
“If I tell you this,” Luna said calmly, “you must promise not to be angry with me. You must swear on your life that you won’t banish me, remove my title, renounce my claim to the throne, or—“ her voice shook ever so slightly, “—or disown me.” Celestia’s eyes softened.
“Lulu,” the older princess said gently, her voice faltering as tears brightened her eyes, “I could never, ever do any of those things. You are my little sister, and I will always love you, no matter what. Now,” she said, draping her wing over Luna’s shoulders, “tell me what’s going on. You’re worrying me.” Luna took a deep breath and explained everything. Celestia’s face turned crimson as she processed what her sister had told her.
“So,” she said coldly, in a voice that was terrifyingly soft and deathly calm with fury, “you asked for that time off because you fucked a guard, got knocked up, gave birth to a bastard foal, left the foal at an orphanage, and then came back here to resume your duties as if nothing happened?” Celestia’s eyes shot daggers at Luna, but the younger alicorn refused to show the fear that churned within her.
“If you wish to describe it in such a crude manner, then yes, that is precisely what I did,”Luna said, her voice clipped and businesslike. “You would have forced me to give up the foal anyway, so I simply expedited the process.” Celestia shook with rage until she could no longer control herself.
“WHAT THE FUCK WERE YOU THINKING, LUNA?” Celestia’s voice cracked the floor in half, and several windows shattered. “WHY WOULD YOU ACT LIKE SUCH A SLUT? HOW COULD YOU BE SO STUPID? YOU HAD ONE JOB: TO KEEP YOUR LEGS CLOSED. I have never been so disappointed in you.” Her voice broke. “Now, everypony will only ever talk about Luna the slut, Luna the whore, Luna—“
“SHUT UP!” Luna screamed, sobbing. “I did what I thought was best for everypony, including you. I didn’t want either of our reputations to be damaged. If I had brought that foal home, you would have killed her.”
“Where is it?” Celestia asked. Luna was silent. “DAMN IT, LUNA, WHERE IS IT?” The solar princess’ cry contained equal parts rage and sadness. Luna chose her words cautiously.
“She’s a filly—“
“That was not my question!” Celestia snapped. “Luna, either you will tell me where your little bastard is, or I will find out myself. The problem must be taken care of, regardless.” Luna’s maternal instinct enveloped her, and she blanched as she discovered the horrific reality that her sister’s words veiled.
“‘Problem’? ‘Taken care of’?” Luna murmured, narrowing her eyes. “Celestia, my daughter has done nothing wrong; she never asked to be born. if you so much as venture within one hundred yards of my daughter, you will pay. What would your subjects think if they knew you harmed an innocent foal?” Her voice was icy. “If you want to punish anypony, then by all means, please punish me; I will give up my immortality if I will spare my daughter’s life by doing so, but hear me now, sister: If you lay a hoof on my daughter, I will show you pain beyond your wildest imagination. You will beg me to let you die if you hurt my little filly.”
Luna’s ears rang with anger.
“Is that a threat, Luna?” Celestia raised her eyebrows. “I don’t think you are in any position to threaten me, you stupid slut. That foal will be done away with immediately. If you weren’t an alicorn, you would be nothing but a common street whore. I—“ the wind was knocked from Celestia’s lungs as Luna smacked her hard across her face. The younger alicorn trembled with pure, unmistakable rage.
“You want me to abdicate? Fine. I hereby abdicate the throne and relinquish the title of Princess of the Night and co-ruler of Equestria, along with all of its privileges, duties, and responsibilities,” Luna spat, removing her crown and necklace and throwing her regalia at her sister, who stood silently, stunned by Luna’s slap. “Now that I know what a cruel, insufferable bitch you truly are, I have absolutely no desire to reign alongside you. I’m going to get my daughter, and you will never have to speak to me again. Have fun ruling Equestria alone.” With that, Luna turned, magically shattered a stained glass window, and flew away.