A Tineey Little Sleepover

After class, Tineey and Cupcake Sweets liked to wander off into the nearby woods. They'd get just far away enough that nopony would notice them in the cover of the trees, then roll out the blanket they'd stashed nearby. Almost every day, they'd plunk themselves down, each let out a long sigh, and bask in the sunlight as it crept through the branches and dense foliage overhead.

The two of them were a peculiar pair, Tineey being the only changeling in class, and an even rarer albino at that, whereas Cupcake Sweets, while a normal filly in most regards, was so well-endowed in the area of her crotch-teats that she put most adult mares to shame. Cheerilee would struggle with either of them to get the class under control, because all anypony wanted to do when they were around was poke and prod and ask questions and treat the experience as some weird show-and-tell. Cupcake took to the experience more eagerly, she loved ponies poking and prodding at her no matter what, but Tineey was a little more anxious under attention, on account of a particular piece of information he was under strictest orders to keep secret.

Cupcake had found out the first day she'd met him, of course. She'd wanted to make friends with the gorgeous new changeling right away, and plied Tineey for the story of his upbringing and details on his family until she was practically a member herself. She'd even given him his nickname, 'Twinkle', and started using it to call him when they were out of class. Oftentimes it made the poor dear blush, which was extra adorable on his pale white cheeks.

Besides her too-big-for-her-age pony-titties, Cupcake Sweets had a colour scheme that complimented her changeling friend well: cream-white coat and wings, and a mane of pink and purple stripes that looked a bit like a strip of chewy candy. Tineey had even caught himself chewing on it once, which Cupcake refused to let him forget about to this day. And though her glasses made her look from a distance like a potential teacher's pet, Cupcake Sweets was far more interested in under-the-desk troublemaking than listening to anything Miss Cheerilee had to say. One game she liked to play was 'see how many boys you can get hard before the bell rings'. No touching; just flaunting her flank and big, bulging teats was more than enough to make any poor colt's cock spring to life, usually with a satisfying thwap as his engorged head hit the underside of his desk. Cupcake was all giggles, but that made her laugh the most, especially when Miss Cheerilee gave the colt a knowing glare from across the classroom.

It wasn't as though Cupcake Sweets ever tried to work particularly hard during the day, nor that she necessarily needed to relax afterwards. It was just somewhere pleasant to be with her friend, who, according to his numerous testimonials, would practically fall apart without an opportunity to decompress before going home. Tineey had a little more stress than anypony else throughout the day, and it was that distress that no doubt prove to be the unlimited source of future problems and opportunities. Today, there was no reason to suspect anypony else would ever find out about it, besides Cupcake, and, of course, Tineey's parents and family.

'It', in terms certain or uncertain, was, essentially, Tineey.

What Tineey really looked like.

He was still as pale as a mid-afternoon cloud; that part didn't change. And his precious pink eyes, white-to-pink tinged horn, ears, and wings. But whether or not it was obvious to anyone by name, Tineey, or Twinkle, as perhaps a more sensible moniker, had always been a bit of a trick. Tineey didn't mind tricks, but they could be very draining when they were necessary to play all day.

It usually took a minute or two for him to feel relaxed enough to... 'do it'. 'Let it all hang out', as Cupcake liked to say.

"Come on," she said today. "Nopony's around. You need it."

Tineey, aka Twinkle, whimpered in agreement.

"I do," he said, voice quivering and eager.

"Then let it out. I'll help you feel better." She put a hoof to her mouth and giggled, jostling her glasses down the bridge of her nose and then pushing them back up.

Tineey nodded, sighed, and relaxed even more into the blanket. He stretched all his legs out, craned his neck around in circles until he heard a tiny crick, opened his eyes wide, and then closed them. His chest rose and fell softly as his breathing became more paced and guided.

"That's it," Cupcake said soothingly, patting along Tineey's stomach the way he liked, to calm him down, ease him along. "Let it all out." She licked her lips. "Then we can... 'relax'. Heh."

Even before his transformation had started, Tineey's cock was beginning to twitch to life.

When his form shifted, Cupcake could help herself, and immediately spread her legs and began rubbing softly at her teats, massaging one, then the other as she stared at Tineey's transformation. As she watched him grow, and bulge, and begin to come undone in the best way she could imagine. She loved seeing him like this, in the inbetween, before he'd completely come into himself again. She loved to call him 'Twinkle' then especially.

Tineey was very big. So big, as it turned out, that had he stumbled into class at full size, they would have struggled and indeed eventually failed to find a desk sufficient to fit him. And it was in that area, the one of most particular interest to a classroom of curious, hormonal foals, that Tineey's name was the most obvious misnomer, because downstairs, there in particular, he was huge, and in such a way that when you saw him next to Cupcake Sweets, his day one in Ponyville friend, the bond between them made such evident sense it was a wonder they hadn't been friends in a past life and simply decided to meet up one day in pony bodies perfectly fitted for each other.

Still, Tineey would protest it was a problem, his size was more for breeding than play, and his past and destiny had been so complicated, wrangled up in one job at birth and another only years later... it all got quite hard to explain, and even if Cupcake was feeling patient, which was rare, she could never sit through the whole thing without waving her hoof to summarize and then diving mouth-first onto Tineey's cock, turning him into 'Twinkle' as fast as her tongue could manage. At full fize, she couldn't really fit the whole thing down her throat, but it felt nice when it swelled and grew between her lips, until finally she had to give up and let the thing go, usually with a loud gasp, and then there was no limit to what the two of them could do, as long as they had a little bit of privacy.

That bit was important—Tineey's parents didn't want anypony else finding out how special their son was just yet. A changeling's destiny was oftentimes more complicated than could be easily explained or articulated.

So Tineey hid himself during the day. He struggled through class, in a form small enough to fit tucked into one of those diminutive desks, knowing that if he lost control, or willpower, or suddenly for some other reason exploded to his proper size, that the desk would go with him, and likely afterwards the attention of everypony in class. He got enough stares being the proverbial odd hoof out already... with his cock and the rest of him at full size, Miss Cheerilee would never manage to get anything done besides him.

His 'cloak' was almost all the way off now. Cupcake Sweets was licking her lips and rubbing her teats eagerly, squeezing her hind-legs together every once in a while and letting out a little moan when she did.

If it was just another day, the two of them would have gone on unnoticed. But as it happened, a particular pair of eyes was watching, belonging to a pastel pink pony with a smile too devilish to spell anything but disaster.

Even so, staring through the trees, the little pink pony couldn't help herself either; she licked her lips as Twinkle's true form came into view.

"This," she said to herself in a sneakish whisper, "is going to be way too much fun..."