Author's Note
Dragk has done some great work for me, so I decided to return the favour. When I showed him this story, he told me that it was 'amazing.' 
But don't take his word for it. You are, of course, free to make your own minds up about what you think.
Enjoy!
One-Shot
It was just another ordinary night in Canterlot Castle, and I was standing outside Celestia's bedroom door. But before I opened it, I decided to take a moment to think.
Celestia has always laboured away her eternal life, never asking for help or for anything in return. She always greets ponies with a happy smile across her angelic face. Her kingdom is all she's ever had, and she cares for everypony who resides in it — although nopony cares for her as much as she cares for them.
Many tears have been shed due to this fact.
But her heavenly white plot with its golden sun cutie mark has always looked astounding to me. She makes me melt like chocolate on a marshmallow of love. She has never felt what love really was, because she could never find the right pony to share it with. She only needs a dash of love to bring out her true happiness, which itself is a truly beautiful sight.
I consider myself to be the luckiest person in existence to have her as mine, and I don't know how life could be any better. I'm the only one she can weep on, share special moments with and – most importantly – share her lustful and romantic thoughts with.
"Oh, dear, I hope he's okay." my thoughts were interrupted by the sound of my goddesses silky smooth voice. "He's never been this late to come and visit me. In fact, he's usually very excited and quick to come and see me."
I opened the door and stepped inside her chambers, taking in the sight of my beloved as she lay by the fire. A pair of glasses was perched delicately on her muzzle, a piece of parchment and a quill floated in front of her, and she was taking a sip from a cup of tea.
Once again, she was so caught up in her work that she failed to notice my presence. I looked over her sleek curves, my eyes drinking in the sight of the see-through negligee she was wearing. Every now and again, I caught a glimpse of her marehood, and it made me smile deviously. Walking up behind her, I put a hand on the back of her head and spun her around.
"Huh— hmph!" her glasses fell to the floor as I pressed my lips passionately against hers. As we separated, Celestia gazed at me through half-lidded eyes. Her mouth was hanging open slightly and her tongue was hanging out, a sight which made me smile.
"Hello, my beloved," I said. "Did you miss me?"
A simple "Ahh..." was all Celestia could muster by way of reply.
I don't know what it is about him, Celestia thought. Maybe he's special. All I know is, whenever his loving hands caress me, I just can't control myself. My mind goes blank, and I turn to putty.
"Where have you been all day?" she demanded. "You know I worry about you when you leave. I bet you went to the Everfree Forest again, didn't you?" She glared at me. "How many times do I have to tell you, there is nothing for you out there? Why don't you ever listen to a word I say?!"
I looked away from her sheepishly. "I... just..." I paused for a moment, then whispered. "I'm sorry."
Celestia sighed and looked out the window. "It's okay, Dragy," she replied. "It's just... I worry about you. I don't know what I'd do if anything were to happen to you." She looked at me and blushed, something that I've always found cute about her. There's no competition for 'Most Beautiful Mare' when Celestia is involved. "I thought... I thought you'd forgotten about our special night. If you didn't come back, I don't know what I'd do with myself. I would be lost, with nopony to care for me like the way you do."
I gasped. "Celly, I would never forget this night, for it is permanently etched onto my heart," I said. "You made me the happiest man in Equestria two years ago, and I love you too much to just disappear. It would wound me to hear or see you cry over something like this."
Celestia smiled. "My love..." she said. "You are safe here with me. Safe and well, that's all that matters now." Her voice took on a more sultry tone. "Now, Dragy, it is still our anniversary for a few more hours — and as you know, hon... it's mating season."
I removed my shirt and lay on the bed, a knowing smirk on my face, while Celestia opted for slipping her negligee down slowly. She spoke to me again, her voice dripping with lust, while her excitement began to make itself known by way of her marehood becoming wet with eagerness.
"I've been thinking all day about you pounding my royal hindquarters," she said.
I love it when she teases me like that! I thought. I didn't say anything in reply, I just parted my legs a little to let her see that I was starting to pitch a tent.
Celestia's eyes widened. "My, my..." she cooed. "You are getting hard at the sight of your princess in heat, am I right?" She giggled. "You are so naughty, Dragy. Looks like you need some discipline."
I shut my eyes and nodded. "So," I replied. "What will my punishment be this time... Princess?"
"I'm going to have to send you to the sun." Celestia replied solemnly. "I'm sorry, my love."
"Okay!" I said eagerly, only to snap my eyes open as soon as I had actually processed what was just said. "What?! The... sun?"
My vision was suddenly filled with a golden sun cutie mark as Celestia backed her wonderful plot onto my face. She was winking like crazy and dripping with lust. "Hmph!"
"Sorry, Dragy!" Celestia said cheerfully. "You leave me no choice!"
She didn't stay there for long, though, presumably because she remembered that I need to breathe, and raised her hips. I trailed my tongue along her flower gently, relishing in her taste and scent.
"Ahh..." I gave her another lick, a thin trail of her excitement connecting her marehood to my tongue as I withdrew.
"Delight yourself with the scent of your beloved Princess in heat!" Celestia proclaimed as I put my hands on her flanks, moving her negligee to the sides so I could get a better look.
"You are such a magnificent mare, Your Highness!" I said.
Celestia began grinding her soaked entrance across my crotch, soaking my trousers through completely. "Enjoying the view, huh?"
"Oh, yeah..."
She giggled, then flared her horn with magic and started undoing the zip. "I'm sorry, my love," she said. "I cannot hold myself any longer." She leaned in and licked my cheek. "I love you, Dragy."
She began trailing kisses further down my body. I've always loved her soft kisses on my lower abs. Ahh, she's so cute...
I felt a sudden coolness downstairs, as Celestia finally freed my shaft from its prison. "Gotcha." she grinned.
She took one of my balls into her mouth and began sucking on it, planting the occasional kiss, while a forehoof found its way around my length and started stroking it. All the while, Celestia was making an assortment of cute moaning noises.
Slowly but surely, she worked my dick into her mouth. A faint grunt left her throat as she took me in, but that soon gave way to another contented humming noise.
"Good girl," I said, putting my hand on the back of her head.
"Mm-hmm..." Celestia shut her eyes and began bobbing her head up and down, coating my spire in saliva. I could see her wetness accumulating on her hind legs as it dripped from her moist sex, and I was eager to get the party into full swing.
With a wet plop, Celestia took me out of her mouth. She smiled at me and unfurled her majestic wings. "My wings are so pretty..." she began trailing them gently along my cock, and I let out a small moan as she took me back into her waiting mouth.
She looked up at me as she worked my shaft, her wings becoming slick with saliva and precum, and wiggled her plot seductively. I could feel the pressure in my loins starting to build up, so I grit my teeth. Celestia noticed this and extracted me again, planting one final kiss on the head.
I put one hand under her chin and used the other to bring myself to climax, sending my load into Celestia's open mouth — although a few stray strands did manage to land on her face.
Mmm, Celestia thought. It tastes so sweet.
"Now be a good girl," I said. "And swallow every last drop."
Celestia opened her mouth and showed me the cum on her tongue. "Like this, Dragy?" she asked. She closed it and swallowed, a loud gulp signalling that she had done as I asked.
I nodded and kissed her cheek. "Turn over, love."
Celestia complied, turning around so that she was facing away from me and finally giving me another look at her exquisite flower.
She was completely soaked, her excitement glistening under the light like stars on a lake. I gently kissed her folds, then used my hands to spread them apart.
"Ahh!" Celestia moaned.
I chuckled. "It seems you are more than ready for me."
I ran my tongue across her entrance, slurping greedily at her precious nectar, and planted the occasional kiss on her exposed clit. Celestia moaned in ecstasy as my tongue danced across her exposed nethers, both of us relishing in the pleasure that was surging through our bodies.
Soon, I decided that enough was enough. I stood up and removed my trousers, pressing my stiffness against Celestia's entrance. She moved her tail to the side and I gently eased my way inside. Inch by inch I slid inside her, the substantial lubrication she was providing ensuring that I met no resistance, only stopping once our hips joined with a satisfying squelch.
I could feel the tip of my cock touching the end of my mare's love tunnel, and the sensation was enough to drive me crazy. And as I began thrusting, Celestia's mane went from flowing in an invisible breeze to hanging limply around her head. It was if she had lost all control over the magic which helped to keep it moving, instead becoming consumed with lust.
I took myself out of her for only a moment before driving myself back in again, our bodies colliding with a heavenly smack which seemed to resonate around the room.
***
With the moon raised and her night sky looking perfect, Princess Luna was in good spirits. She left her bedroom and began the walk to the throne room, where Night Court was due to take place. But as she walked past Celestia's bedroom, a sound caught her attention and made her stop in her tracks.
"Hmmff..."
Luna stifled a giggle. She probably got caught up in paperwork again and lost track of the time, she thought. I'd better go in and tell her to actually take a break for once. With this thought in mind, she gently opened the door and poked her head inside.
"Sister, w—"
The words died on her tongue as the sight of Celestia being fucked by Dragk filled her vision. Luna's eyes shrunk to pinpricks and her cheeks turned bright red while she stood rooted to the spot, unable to tear her gaze away from the sight before her.
"Mmm, Celly..." Dragk grunted, as he slammed into her at a blistering pace. The human had Celestia's tail draped over one shoulder and a firm grip of her wings, using them as leverage to guide himself in and out of his mares glistening sex.
"Ahh!" Celestia cried. "Ahh, Dragk!"
Luna stared in awe as the scene unfolded, while a forehoof found its way between her hind legs. Staring through the crack in the door, Luna began gently rubbing at her marehood — while she watched her sister get hers filled with the humans seed.
Dragk grunted as he came, filling Celestia's love tunnel with as much cum as he could muster. As he withdrew his spent rod, some of his deposit seeped out of Celestia's winking entrance. He buried his face in her mane, both of them panting profusely.
Meanwhile, Luna had closed the door and returned to her room.
Night Court would not take place this eve.
***
I held Celestia tightly as we both came down from the highs of our respective orgasms, kissing her on the cheek.
"I love you..." she whispered.
"I love you too," I replied.
I let go of her and she rolled over, looking up at me with part of her mane obscuring one eye. "Hey there, handsome." she smiled.
I produced a flower and put in her mane. "Happy anniversary," I said, giving her a smile in return.
"Aww, Dragy..." a faint blush appeared on Celestia's cheeks, but it quickly faded as she lay on her side and ran a forehoof through her mane. I could see my seed dripping out of her, and it made her look all the more spectacular. "So... how do I look?"
"You look amazing, hon," I replied.
"I'm glad you said that," she said. "Because we're not done yet."
She pushed me onto my back and straddled my crotch, before pushing herself down on it. "I hope you don't mind going for a ride with your little pony." she giggled. "So just relax and let me take care of you, my dear prince."
"Got it!" I nodded eagerly, as our hips met with another squelch.
And then Celestia started riding me like a mare possessed.
It was too much for a mare of her age. At this point she was tired, hot and sweaty — but at the same time, she had never felt better in her life. She just couldn't stop!
"Ahh... mm... yes!"
She felt younger, bouncing on her lover's cock like a little filly.
"Dragy!"
She was loving each and every second that ticked by — and the only thing on her mind was me. The beads of sweat running down her body were like jewels, glistening in the light and making her look all the more beautiful.
Little sexy moans left my beloved while I reached up to engage her in a passionate kiss, our hips squelching and smacking as we grinded against each other. I put one hand at the base of her tail and the other on one of her flanks, slamming into her with gusto.
"Who's a good pony?" I asked.
"I— ahh!" Celestia shuddered in delight. "I'm a good pony!" I smacked her on the flank. "Ohh..."
I could feel myself approaching my peak again, so I began thrusting even faster. The room was filled with the cacophony of our love: moaning, groaning, squelching and smacking. It sounded amazing, but we both knew that this was one particular tune which had to stop playing eventually.
"Oh, gosh, I'm so close!" Celestia squealed. "Dragk, don't stop! I'm yours, all yours... only yours!"
"Oh, Celly!" I grunted. "Let's do it together!"
With those words, we both came. A wave of pleasure washed over me as I emptied myself into Celestia's waiting entrance for the second time that evening, my vision turned white and for a moment the world was lost in a haze of euphoria. I could feel Celestia's own orgasm seeping down my crotch, which only served to heighten the bliss I was enduring.
"Haha... ahh... ahh" Celestia panted. "Dragy... that was awesome." She kissed my cheek. "You... you are my stallion."
"And you are my mare." I kissed her back.
I pulled out of Celestia's dripping marehood and pulled her down next to me, hugging her tightly. The moon was high in the sky, bathing Canterlot in its soothing glow, but all I cared about was the warmth of the mare who was lying next to me.
Celestia sighed contentedly and buried her muzzle in my neck, letting the lull of sleep finally catch up with her. As I ran one hand through her mane, something falling onto my chest caught my attention. I looked down at it, wondering where it came from, when another thing joined it. I put a hand on my head and felt around.
"What are these things in my hair?" I mused.
I shook my head to clear out the rest of the offending objects, though I got a hold of one and took a closer look at it. It was small and white, and almost looked like a star. The window was closed, so how it got there was beyond me.
Shrugging, I flicked it away and settled down to get some sleep with my beloved Celestia.
My warmth, my light, my everything.
