Luna prowled. It was an activity she had much experience with, and even enjoyed. She stalked through the hallways of Twilight's castle, exploring and surveying her temporary territory. She walked with deliberate care, minimizing the sound of her hooves striking that hard stone.

It must have worked, seeing as Spike made such a delightful squeal when she came up upon him.

She assured him all was well. He assured her he wasn't really scared. She didn't believe it, but didn't press the matter and left him with well wishes.

The moon was rising high. Celestia was doing her part... Both of their parts. Celestia had done it before. Seeing it made Luna feel... diminished. It was a reminder that she was not truly... required.

Of course, there was one matter only she could tend to.

She stepped gently towards her room, determined to get to it. Even if she was nominally 'off duty', she would not let that go. She was the only one. That pleased her. She had a vital part, and she would not fail it.

Just as she was reaching for her door, a bright flash heralded the arrival of a unicorn. Twilight? No, her other student. Luna was dissapointed, but did not begrudge Starlight. "Good evening."

Starlight nodded. "I was hoping you'd be here."

"Is there something you require?"

Starlight sat. "Twilight's been giving me... bit of a crash course, on you that is."

Twilight had been speaking of her? Luna felt warmth build. "Has she?"

"She has, nothing bad, I assure! She said you guard dreams and control the moon." She pointed at the large Luna. "I've been having..." She trailed off, looking embarrassed.

Luna knew that embarrassment, and the lesson just reminded to her. "As your friend, you can trust me. Please, ask. I will not make light of your troubles."

Starlight smiled a little. "I don't like not being in control of my life, and... nightmares. I can't control when they happen or even what I do in them. I hate it. Can you make them stop?"

Luna perked an ear. She didn't remember any night terror powerful enough to draw her direct attention, but she had a whole kingdom to monitor. Things could fall through the cracks. "Tell me of them, and how often do they occur?" She opened her door with her magic and gestured for Starlight to enter.

Together, they stepped inside and soon were sitting across from one another at a small table. Starlight rubbed behind her head with a hoof. "Say two or three times a week? I imagine I'm back at my old town, the one I sorta had brainwashed." She brought the rubbing hoof forward and rolled it. "They'd all be smiling, like they used to do. They'd say nice things, do nice things. I'd be so happy, knowing I helped make such a happy place, but... then..." She shuddered with the terror of it. "They'd turn on me. They'd start to scream and shout. My magic wouldn't work on them at all and they'd chase me from the town in an angry mob. I'd always get away, but, dream stuff, I'd see the town again, and the ponies would all be happy. I'd just not be there. That happy place I made was not for me. That's usually when I wake up."

Luna frowned softly in thought. "Have you considered the message of this?" That was not a nightmare severe enough to summon her. It was a lesson trying desperately to be heard.

Starlight leaned back. "If it is a message, I don't get it. I'm not trying to br--"

Luna raised a hoof. "You controlled the mind's of Twilight's friends."

Starlight turned a bright red. "That was different! That was mind control. Mind control and brainwashing are... different. You don't need magic to brainwash ponies."

Luna raised a brow. "Be that as it may. Starlight, as your friend, I must inform you that they have a common thread."

Starlight tilted her head just a little. "What's that?"

Luna pointed at Starlight. "You want to control those who would not wish to be controlled. You do not know how to be in a relationship without being the controlling party. When that is broken, you falter."

Starlight hopped to her hooves. "Look who's talking there! You! You want to be controlled! How is that any better?"

Luna gestured to Starlight. "I do not impose my desires on those who do not wish it. It is... true, yes. Twilight does exert control over me, and I allow it. Therein lies the difference. We both agree to the social tie that binds us."

Starlight clopped a hoof down with an angry grunt. "I don't understand ponies! They act... so strangely. I don't get it. I want to understand! I do, I swear!" She approached Luna and reared up, her forehooves on Luna's chest. "Why don't ponies make sense?"

Luna's magic glowed around Starlight's hooves, gently lowering them to the ground even as she leaned in. "That is a lesson we both need, and what binds us together. Twilight understands this. We learn at her hooves."

Starlight huffed softly and things grew quiet between them a long moment. "So, why not me?"

Luna blinked. "Why not what?"

Starlight put a hoof to her own chest. "Why not me to be your mistress?" She half-lidded her eyes. "I have experience."

Luna felt heat rise in her cheeks. "I do not know you that well, my senior student. I am un--"

"I understand." Starlight sagged a bit. "I guess who would ever pick me over Twilight, I am perfect, Sparkle."

Luna clopped a hoof on the ground. "Twilight is my teacher. You are... better educated than I in this matter, but not close to her level. Twilight is far from perfect, but in this matter, she is above either of us. Now, I have told you what I may. If you like, I will visit you in your slumber and be sure the nightmare is not damaging."

Starlight's eyes widened faintly with a new idea coming to her clever mind. "Oh, yes. Please. I look forward to seeing you, junior student." She rose to her full height. "Until then, goodnight, and thank you."

Luna watched her depart before nodding to herself. She had handled that well, or so she decided. She settled on a rug spread out in the middle of the room and closed her eyes. It was time to send her consciousness into the ether between minds.

It was a productive night. She calmed several night terrors and gently guided some citizens that required her gentle hoof. She loved helping them. She loved the other ponies, even if they confused her at times. She frowned a little. That made her think of Starlight, also confused about her fellow pony. That was surely one thing that tied them.

With that reminder, she took off at a stately walk through the dream world. She had a pony to visit in particular.

She pressed her snout through the membrane that held Starlight's dream safely from the others, and slid free to a mound of cushions that caught her gently.

"Luna," spoke a familiar voice. Starlight was there, a cocky grin on her face. "I started to wonder if you would ever appear."

Luna blinked. "Are you lucid?"

"I am." Starlight nodded. "I only lose control of myself when a nightmare comes. Another reason to hate them, but let's put that aside for the moment..." She raised a hoof and brushed against Luna's flank. "You've been a very naughty student."

Luna jerked in place. Had she?! What had she done wrong? She opened her mouth to ask just that and Starlight's magic sealed around it, slowly forcing it closed even as it pet and scratched along her snout.

Starlight hovered up, snout to snout. She looked to Luna with a smoldering gaze. "You will not speak unless asked a question or told to. You remember that rule, do you not?"

Luna nodded faintly. When did Starlight become the one giving orders?

Starlight clopped her forehooves. "Excellent, now... I remind you, I am a caring mistress. You are not here to be abused. You... are a majestic creature, even if you are a dirty and misbehaving student." She licked over her snout. "We will have to discipline you, but I suspect you won't mind it terribly much."

Luna felt heat run through her. Starlight was playing her, and it was working. She still didn't quite understand it all, but part of her was lit right on fire by Starlight's commanding tones.

"Oh, what's this? Your sins grow, student." Her magic reached and swiped in a sudden stroke over Luna's petals. Luna squeaked in surprise even as the magic came back around, holding moisture aloft. "Look at this mess you're making."

Luna hadn't even realized she was doing that, and yet, there was the proof. "I..."

Starlight put a hoof to her snout. "The rule."

Luna remembered swiftly what that was. She also remembered... she was in a dream. She was Luna, master of dreams, princess of Equestria! Who was this unicorn to give her such orders? Why, if she had it in mind, she could--

Her thoughts came to a sudden and crashing halt as she felt attention between her hindlegs and a pleasure to go with it. She glanced back there and saw Starlight was gingerly dabbing her nethers with her tongue as if sampling her. What was she doing?

"Student, roll over onto your back and tell me what you feel. Speak of nothing else."

Luna slowly did roll over, even as she wondered why she was doing so. She could crush that smug unicorn with barely an effort. She could... Luna let out a soft moan as Starlight began to lick and nibble gently at her in earnest. That smart mouth did have a use, and Luna could find little fault in it when it was wielding a soft tongue instead of a sharp one.

"Tell me what you feel," spoke Starlight sternly. "Don't stop."

"I... feel a powerful tense shudder every time you... lick. When your teeth touch, I feel an involuntary moment of terror followed by a spike of delight." Luna closed her eyes. Describing the sexual encounter was something new. "I feel exposed."

"You are exposed." Starlight nuzzled into those damp petals. "Exposed, vulnerable... I could do terrible things... but would I?"

No. Luna felt certain the harder Starlight worked. Starlight was a good mistress. She would never hurt her. A sudden wave of tightness gripped Luna's body before her cry almost shattered the delicate dream world. She climaxed with almost frightful intensity, left weak and panting, and yet wanting more, so much more.

Starlight wasn't giving it. Reeling a moment from the shock her own dream had endured. "You are a powerful student, and yet, still mine." She set a hoof on Luna's lower belly. "If you're a good student, I have much more... creative rewards for you. And, should you prove naughty, my punishments will be most unkind. I will be listening to Twilight, and asking her. Don't think you can get away with disobeying one master without the other hearing and taking action, oh no..."

Luna felt the dream starting to dissolve. That shock was waking Starlight up. The dream would be over in a moment. She rolled up quickly, just in time to be ejected back into the dream world.

She had much to consider.

Author's Note

Starlight gets to be a dom without breaking friendship rules, this pleases her greatly. She just wanted to make ponies happy, now she has one that she can dom all over without hurting feelings or resorting to mental warfare or magic. How delightful!

She will gladly take care of Luna.

A new best friend.

How did you like it?