The Curious Tale of Dr Shine and Ms Sparkle.

“What do you mean our son Dusk was seen at the hospital?” A middle-aged mare questioned, she frowned at the apparent news.

“I’m telling you Velvet,” The stallion she was talking to replied, “I’m sure it was Dusk, he was all dressed up like a mare and he was with some stallion.”

Twilight Velvet looked at her husband in disbelief, and wondered why Dusk would be dressed up like that. She didn’t have anything against ponies who did that sort of thing, but her youngest son? She couldn’t help being concerned. Velvet hoped he would find a nice filly and settle down, but maybe that was just her being something of a traditionalist.

“Are you a hundred percent sure it was Dusk?” Velvet asked, “I’m pretty sure Dusk wasn’t into stallions Night.”

“Well why else would he be here in Canterlot?” Night Light argued, “The only other reason he would be here would be to visit us or the Princess.”

“Hm...” Velvet paused for a moment, “Well maybe a visit to Ponyville is due, I’m sure Dusk and Spike would be happy to see us.”

On the way back home from the train station, we ran into Rarity. I could see she was upset about something when she saw Mac and I together but before I could say hello she had ran off without a word.

“Jus’ give her some time Dusk.” Mac spoke up, as he stopped me from running after her.

“Do you know why she ran off like that?” I asked him.

“...Ah do, but...” Mac paused, “It ain’t mah place to say...”

“Maybe I’ll ask her later...” I replied, I couldn’t help but wonder if it was because I was with Mac.

As we walked through Ponyville, I couldn’t help but notice all the glares I was getting from the other mares we passed by.

“What did the doctor tell yer?” Mac inquired, “Yer never said anything about it on the train.”

“O-oh...well.” I paused for a moment, “The good news is I can reverse it, and it isn’t going to get any worse...but the bad news...it’ll be pointless to even try, as I’ll just revert back to this body eventually.”

“Ah see...” Mac thought for a moment, then saw my worried expression, “There’s something else ain’t there.” I nodded.

“I...don’t want to change back...” I admitted quietly, “...I never want to change back...”

“Dusk?” Mac raised a brow, surprised at what I had just admitted.

“Mac...” I continued, “...I never want to go back to being a stallion ever again. I don’t care what I have between my legs, and it’s because of Twilight we’re together in the first place. Every time we’ve been together...physically it was you and Twilight...” I paused for a moment, “What I did on the train, was the first time I did something like that without Twilight influencing me or turning into her.”

“So...ya’ll were worryin’ Ah was only with yer because of Twi?” Mac asked, I nodded slowly.

“I guess I kind of was...” I said truthfully, “I don’t want this relationship to be just about sex...and well could you blame me for being a little jealous of Twilight...and I...a-and...I-I...” I was beginning to feel that wonderfully addicting warmth slowly wash over me again.

“Dusk?” Mac recognised what was happening to me, “gosh darn it not in public...” Mac picked me up bridal style, and began running as fast as he could.

I could feel my breathing become heavier, and my heartbeat race as I squirmed in Mac’s arms. I had to cover my mouth so myself from moaning from the raging heat washing over my body, I wanted more, I craved more...I needed more of this feeling.

Mac ran as fast as he could to the home of the nearest pony he could trust, and hopefully somepony who wouldn’t judge Dusk for what was happening to him.

“Rares!” I pounded on the front door of her boutique, “Rares open up! Gosh darn it Ah need yer to open up right now!” The door was open by a very distressed Rarity, who’s cheeks were stained by the make up from crying.

“M-Macintosh...?” Rarity looked confused, before noticing me squirming in his arms, “D-Dusk? Oh my goodness what’s wrong with Dusk? Come on in!”

I couldn’t hold it back any more, this feeling was getting too much and yet I wanted more and more of it. I consciously reached down into my panties, and felt a relief when I felt something moist and wet.

“D-Dusk! T-this is hardly the time for this!” Rarity let out a disapproving glare.

“Ah...she can’t help it when she gets like this Rares,” Mac interrupted, “Trust me, ya’ll see why in a moment or two.”

I could feel it, the wonderful feeling of my body changing. My breasts getting larger and larger, just swelling up and stretching the top of my dress tighter as it showed more and more cleavage. Part of me hoped I would spill out of this dress, then again I was loving the way tightening fabric was rubbing against my sensitive puffy nipples.

Rarity watched on as her friend was going through some sort of transformation, she couldn’t believe how lewd Dusk sounded and the utter shock of how he was rubbing his crotch...like she had done many times in the past.

“O-oooh...” I moaned, my voice becoming more feminine by the second. I could feel my panties getting tighter and tighter, as my hips got wider, my sweet sexy ass getting plumper and plumper. I feel like a such a naughty sexy filly. I couldn’t help but put my swelling ass up on display, hoping it would entice Mac to fuck me...I could see him in the corner of my eye, and how hard he was getting in those slacks of his, “M-Mac...do you wanna fuck me with that big hard cock of yours?” I swayed my ass hoping to get his attention, “I’ve been such a naughty filly...” I gave Mac the cutest pout I could, but he wasn’t budging an inch from where he stood.

“DUSK SHINE! CEASE THIS LEWD BEHAVIOUR AT ONCE!” Rarity shouted, a bright crimson blush on her face, “H-HOW COULD YOU BE...SO...SO UNCOUTH!!”

I felt the final parts of the change finish as that wonderful feeling faded away, I ignored it as somepony had caught my full attention. I stood up as best I could and I glared at Rarity.

“I-it can’t be...y-you’re that mare from the other day...” Rarity stepped back, “W-Why are you glaring at me like that?”

“I’m still not amused with you considering what you did to Duskie Rarity.” I growled, “Though for Duskie’s sake I’m trying my best to forgive you.”

“J-Just what is going on?” Rarity slumped down on her knees more confused than ever. I sighed...well she was going to find out sooner or later.

Mac and I explained what was going on, while Rarity just looked completely dumbfounded. This change was something I hoped I could keep private for a little while longer, by the stars I dreaded my parents reaction to this.

“So let me understand this Twilight,” Rarity finally spoke up, “Dusk had an accident, a spell gone wrong to be exact and know he’ll turn into a beautiful, well endowed mare completely at random.” I nodded, “And not only that, the change itself is something Dusk can’t help but be addicted to.”

“Yes that’s it in a nutshell Rarity,” I stated, “I think only Pinkie and Fluttershy is the only ponies out of our friends who don’t know yet.”

“Dear do you have any idea how stressful this must be to Dusk?” Rarity asked, trying to regain her composure, “I’ve seen what these changes have done to his body.”

“I’m fully aware Rarity, and I’ve already discussed the matter,” I answered back, “I went to see my family doctor, and she told me there was no way to undo the changes...at least not permanently.”

“What if there was a cure?” Rarity asked out of curiosity, “Surely you could come up with one.”

“Rarity...” I hesitated, “Even if there was one, Duskie would destroy the cure the first chance he got, and I’m sorry to say I would destroy it as well.” This worried Rarity greatly, I could tell by her expression, “Both Celestia, Cadance and the doctor confirmed it, there is simply no way to undo this.”

“So this is what he meant by he had to learn to live with this...” Rarity sighed, and Mac just stared at me in shock, “There’s more isn’t there...”

“The longer Duskie goes without changing, the more intense the next change is going to be...and it’ll get to the point we’ll both be driven into a lust filled frenzy.” I continued, “I’ll more or less fuck anypony in the room with me when we get like that...It’s not something I’m proud of.”

“This really is a problem isn’t it?” Rarity commented, “Well like what I told Dusk, my offer of help still stands. Just please try to keep this private...a-as much as I enjoyed seeing Dusk like that...”

We said out goodbyes, leaving Rarity plenty to think about.

Omake:

“Well Ah better be goin’.” Mac pointed to the explosion of confetti and brightly coloured streamers in the distance, “It looks like mah sister could use a hand.” He deadpanned, if you listened carefully you could faintly hear Pinkie Pie and Rainbow giggling like crazy. Many of the passers by looked at the explosion, and shuddered recalling the events of the other day.

“Oh no Mac,” I grabbed in by the collar and dragged him indoors, “You’ve got something other than fields to plow first. Duskie had his fun on the train, now it’s my turn.”

"B-but Twi..." Mac tried to argue.

"No buts Mac," I giggled, "I saw how hard you were at Rarity's, you liked what you saw and now I fully intend on fucking you on every flat surface we can find."