"M-My... My what?" Sprout asked, as he pushed himself up to a sitting position, and was immediately and gently magically picked up by Izzy and floated down to the floor in a standing position.

"Your sparkle! It's also called luminescence. Your happiness!" Izzy told him gleefully, as he made his way over to the playpen, his nearly-clean diaper crinkling with every step. "Yours is... A lime green!"

"Uh huh..." Sprout said, wondering if Izzy was crazy or serious right now. On one hoof, what had just happened on the changing table would make nearly any stallion happy. On the other hoof, this was punishment, and he didn't really imagine himself enjoying it.

But as he made his way over to the playpen, his back legs wobbling a bit in the afterglow, he began to realize that he hadn't felt quite as miserable as he had that first night. When he had begun to accept it, and settle in a bit, it began to feel just a little better. His biggest fear was being seen like this, being judged, laughed at, and honestly, his mom and Izzy had done nothing of the sort. The fact that the unicorn was treating this like a regular foalsitting job was, quite frankly, impressive.

Izzy opened the playpen gate for him, and he stepped in, and to his surprise, she followed him in.

"So what are these? They look fun!" Izzy asked, glancing at the various sets of Ponebloks that he had sorted. Only about half of them had been put together. The rest of them sat in semi-organized piles along with their instruction booklets, as they awaited assembly.

For the first time, Sprout felt a little self-conscious about the plastic building toys that were scattered around the playpen.

"Um... ZUFS... That, uh, that stands for Zombie Unicorns From Space..." The stallion said uneasily. He saw the unicorn's eyes widen, and just as he expected her to scoff in disgust, her expression went to a widening open-mouth smile.

"That... Sounds... Awesome!" Izzy said, tapping her front hooves excitedly. "What's the backstory?"

The padded stallion was initially taken aback by the unicorn's instantaneous enthusiasm, but as she continued staring down at the toys awaiting his answers, he figured he'd better start explaining.

"Well, these over here are the unicorn zombie horde. They came down to the planet on their mothership to try to increase the size of the horde," Sprout explained, motioning to the completed large flying saucer toy, by far the largest set he had. "These over here are the ponies who have already been infected. They grow horns and try to spread the Horny Virus as far as they can," he continued, pointing to incomplete carriages and trolleys, with multiple zombie figures. "And over here is the Resistance, who use whatever vehicles and mechs they can find to try and hold off the horde as they find places to hold up and hide, create a community, and try to find a cure," Sprout explained.

It was clear that his foalsitter was positively enthused.

"Ooh. So, what do you say we get the rest of these put together and get this adventure going?" Izzy asked, sitting down at the closest zombie horde set that had not been put together. "Let's keep it authentic. You be the resistance, and I'll be the zombies. Sound good?" She asked.

Sprout nodded, a smile spreading across his face. He hadn't had a playmate with these things since the first time he had put all of them together with Hitch back in his colthood. He sat down in front of the closest resistance set that he had not put together yet, and flipped open the small booklet to the first page, as Izzy did the same with one of the infested unicorn zombie vehicles that had not been put together yet.

As he tried to focus on putting his own sets together, he was continually fascinated at how Izzy used her magic to float several pieces up to the bigger whole, and snap them on, as hers came together much quicker than using hooves. The unicorn had noticed the earth pony's fascination, and smirked at him.

"You better hurry up over there before my zombie horde is ready," Izzy warned him in a teasing tone, and he gave a giggle, flipping the page of his instruction booklet. As he continued piecing his current vehicle together, he couldn't help but notice how pleasant the fresh scent of foal powder was as it wafted out of his diaper up to his nostrils. It was almost relaxing, if it wasn't for the subtle hints of stallion spunk that was still rising up along with it, that kept reminding him that he was an adult getting a foal treatment.

"Oop, almost forgot..." Izzy said, looking back at the changing table, and her horn lit up again, and Sprout noticed the pacifier that had been sitting next to the bottle of mineral oil begin to glow and sparkle, rising up and floating across the room, stopping directly in front of his face, and he saw Izzy smirk at him. With a soft smile, he parted his lips and teeth just enough to have it popped in.

Though he was trying increasingly hard to focus on piecing together his current Resistance Utility Vehicle Ponebloks set, he couldn't help but notice how content he felt right now, as he began to quietly suckle on the pacifier. He had started to feel a little bit of it with his mom throughout the day yesterday, but after not even an hour with Izzy, he was feeling a bit more carefree, and he felt more of his worries just slip quietly into the back of his mind.

He would never admit it, but right now, this situation he found himself in was beginning to feel less like punishment and more like... Therapy.

He was certainly willing to bet that even with whatever his mom was paying the unicorn for her services, this was much cheaper by the hour, too.

Author's Note

Hope you're all enjoying the story so far. Today I thought up some short ideas to toss in here to make the approach to the conclusion seem less abrupt. We'll see how those pan out.

As always, thanks for reading!