It had been two days since I had my date with Mac. I had enjoyed every moment of it, and I looked forward to our next date, right now however I had a much different problem to deal with right now.

“W-why do I feel so empty right now?” I hadn’t changed into Twilight for the past two days, Twilight couldn’t figure it out either. I wondered was there some trigger for the change to happen, “Thank the stairs everypony is out right now...I don’t think I could bare them seeing me like this.”

This feeling had been getting worse and worse over the past few days, I felt so cold, and empty. I missed that warm feeling that washed over me when I changed, just why wasn’t it there and why am I feeling this coldness now?

“Are these changes just random?” I asked nobody in particular, “I thought they were fuelled by my desire?” I must be losing it, that has to be it.

Cadance and Shining were going to be here for another day before they had to go see Celestia back in Canterlot, and then back to the Crystal Kingdom.

“It was nice having my brother and Cadance here, despite what’s happened over the past few days. It’ll be weird with just Spike and I here again.” I mused, hoping to take my mind off that cold empty feeling. “C’mon Dusk don’t lose it now.” I shook my head, and went about doing my daily chores.

The cold, empty feeling got worse over the course of the day, but I did what I could just to ignore it. I could barely focus, and my hands were shaking.

“D-damn it all! W-why am I getting like this?” I cursed under my breath, “I-I don’t need this...t-the heat...i-I don’t...need i-it.” My breathing was getting heavier, “I-I...d-don’t n-need to be...bigger...c-curvier...h-hah! I-I...d-don’t...need to....n-need...to...Oooh Fuuck!”

A very familiar warmth rushed through out my body, it was setting my nethers on fire. I missed this feeling, I wanted this warmth, I needed it, I craved it and it’s absence only made me want more of it.

“Y-yes!” I moaned out in pleasure, I could hear my heart rate racing and my breathing getting heavier by the moment, “C-change me...p-please...m-mor-oooohh f-fuck yes!”

I felt my stallionhood regress once again as it always did, I couldn’t resist the urge to rub myself through my jeans. I couldn’t help it i just wanted to my clothes to tear and rip as hips getting wider, my ass swelling up, my thighs getting thicker and my breasts getting bigger and bigger by the second. The thought of bursting out of my clothes was making my pussy wetter than it’s ever been.

“FuckfuckfuckfuckFUCK!!!” I was practically screaming in bliss at this point, this was the most intense this feelings been. I was so fucking horny right now, fuck keeping quiet...If Shining came back now... “Ohh more...p-please more...I-I need it!”

My chest swelled slowly in size becoming more and more sensitive, I couldn’t resist the urge to fondle my breasts through my shirt as they grew. I loved that my shirt was getting tighter, and tighter.

“G-grow...g-get bigger...” I moaned, as my breasts grew more and more, “O-oh fuck...I-I just want...to...oh fuck.” A button popped off from the strain of my expanding bust. I couldn’t help but titfucking Mac’s cock with these swelling sensitive breasts.

I bit down on my lower lip as I felt my hips, thighs and ass straining the fabric of my jeans, I could feel my panties getting tighter and tighter.

“C-C’mon...r-rip...f-fuck...I-I want be bigger...” As if on cue my jeans began tearing themselves apart with a loud rip. I let out a low grow, something inside me snapped as the raging fire had turned into an inferno.

My mane lengthened, my face softened and my lips became fuller as I lost myself further and further in this blissful heat.

“Hey Dusk I kind of forgot some...oh no...” Shining just watched me in my state of uncontrollable bliss, I growled up seeing my older brother...m-my sexy...hunky...older brother... “D-Dusk what are you...woah?!!!”

The next thing Shining knew he was pinned against the wall, as I pulled him into a kiss. I couldn’t control myself, as I made my way down till I was on my knees and ripping apart his jeans. He looked at me horrified, unable to move as I had him pinned with my magic.

“I’m going to suck you...fuck you hard...” I growled out, “And if Cadance comes in while I’m fucking you...well I’ll fuck her to.” I jacked my big brother’s cock, letting out a devilish smile as it got big and hard for me. I licked and teased it a little, “Oh...so big and hard...and all for your little slutty sister, I can’t help myself Shiny...I need this...so fucking much...” I took my big brother’s cock into my mouth, bobbing back and forth. I couldn’t help but smile as my brother moaned.

I savoured every inch of Shining’s dick, as I maliciously teased him. My clothes felt so constricting...The next thing I knew I was pulled of my older brother and into Cadance’s grasp.

Cadance seemed to be lost in the same sort of lust I was, and the next thing she did was pull me into a passionate kiss. It didn’t take long for me to lose myself again to whatever was urging me to do all this. The kiss became rougher and rougher, as began literally tearing and ripping each others clothes off.

Cadance took delight in ripping my panties off and going to town on my soaking wet cunt.

“H-Haah!” I groaned out, unable to keep myself from squirming. Shining couldn’t help but watch his wife tease him with her lush plump ass, that was just daring him to fuck her as she went to town on his younger brother turned sister.

“Mmphf...Shining?” Cadance groaned, as her husband began fuck her tight pussy. I was just melting into her touch and skilful flicks of her tongue.

“N-no fair...oh fuck!” I moaned, “I-I want Shining to fuck me!” Cadance shot me an amused smirk, and I felt something weigh me down so I couldn’t move.

“Shining’s mine Twilight...oh fuck...and only mine.” Cadance teased me, as she gently trailed a single finger around my clit, “I’m sorry but you’ve been such a naughty filly. Do you want to suck him? Fuck him? Have him cum all over those big tits of yours?” I nodded, and she chuckled, “Well maybe I might share...” She clicked her fingers and the next thing we knew we were in my bedroom. “Oh Shining...” She teased, “Be a good stallion and fuck us both! I’ll so something special if you do...” My older brother just nodded and began to fuck my pussy as hard as he could.

“F-fuck me! FUCK ME!!” I screamed, as I felt something else build up inside me.

“See Shining likes...big, curvy mares...” Cadance moaned as she teased her own clit, “and I do mean very big and curvy, I mean look how hard he’s fucking you now?”

“Ohfuck...!” I could feel my breasts, hips and ass swell even larger than they normally are, Shining was pounding into me even harder like a stallion possessed, “Bigger...f-fuck me bigger!!!” I groaned with each bit of growth, “DAMN IT SHINING!” I screamed, “FUCK ME! FUCK YOUR SLUTTY SISTER!!”

Cadance was loving every moment as she herself grew with me, our tits slow becoming the size of beach balls, with a soft plump marshmellowy ass to match.

“Oh Shiny...be a good colt and fuck your wive’s nice tight wet pussy.” Cadance teased seductively, “Would you like that Shining? Making me grow as you fuck me?”

“Oh fuck...” Shining grunted out,

“Aw...are you close yet Shiny?” Cadance continued, as she stood behind and rubbed her oversized tits against his back, “Do you wanna cum in your little sister? Make her bigger just for you? You like it when I get like this don’t you?” She whispered huskily into my brother’s ear, “Mm I just can’t help myself seeing you fuck Twilight...Do you like having a slutty wife and sister?”

With one final roar Shining came hard into my pussy, and he just kept fucking me as he came, draining those balls of his as I let out one final scream of pleasure.

Cadance stood there as her husband and sister in law passed out on the bed, slightly dizzy and unsure of what just happened. It wasn’t long after she herself had passed out.

“H-huh?” I groaned, I felt so sore...in a good way weirdly. I looked down and wondered why I was naked, “W-what happened?” I looked around and realised I was in my bedroom, I caught of glance of the time. “Did I nap or something? Last time I checked it was only midday.”

“Jeez Dusk could ya keep it down...” Someone behind me groaned, I turned to see my older brother there just as naked as I was...

“Mmm five more minutes Shiny...” Another voice groaned, most likely belonging to Cadance. I grabbed the closest thing to cover my chest.

“What the hell are you two doing in my room!?” I yelled, Cadance and Shining shot up fully awake, and realised their state of undress.

“Oh no, did I lose it again?” Cadance muttered, “The last thing I remember is sensing an overwhelming desire...” Shining looked even less happy.

“Both of you did...” Shining groaned, “I can’t believe I fucked my little brother...” I felt my heart sank a little.

“Oh by the stars no...” I panicked, “I’m not a slut...I’m not a slut...” I repeated over and over again. I lost control again, how could I have let this happen?

“You’re not like that Dusk.” Cadance pulled me into a hug, “I lose myself like that sometimes myself, and well...how do I say this?”

“You’re a complete and utter nymphomaniac.” Shining suggested, “Remember our wedding night? By the stars you’re a complete size queen.” Cadance giggled at the memory.

“Oh and who demanded we both fuck each other until we grew out the hotel?” Cadance smirked, “I had to wipe the memory of everypony who saw us...” Cadance turned to me, “Now Dusk there’s no need to be shy around me.” Cadance grabbed the pillow and tossed it aside, “Oh...my...”

I blushed as I covered my breasts in embarrassment, I didn’t want them to find out how far my body had changed.

“Shining could you get dressed and make something to eat? I need to have a private chat with Dusk.”

Author's Note

Quick bonus chapter for you all.

• silent out.