@Background Pony #45F5
ooh, or maybe even later also this one >>13574

@Background Pony #C698
I was thinking something similar.

@Background Pony #88F9
Loved it!
My headcanon of course is that this culminates in >>44719 or a diff busty Twi post at least for the Mel, assuming the other guy transforms into a different pony

Content: TG/TF

His footsteps echoed across the vast, empty facility and its abandoned pipeworks. Sunlight was streaming in through cracks in the transparent roof panels, playing on the oilslick surface of the weird retaining pool in the middle of the building. Sitting on a ledge was the very feminine shape of his friend, back turned to him, looking out across the oddly-moving fluid that rippled without breezes. The purple ears twitched with each footfall. The multi-colored tail swished idly from side to side.

“Thought you might be here,” Bert said as he approached his pensive friend. “Everyone is worried about you, you know. Should I tell them…?”

“No,” the girlish figure replied softly, still gazing out on the condemned facility as if overlooking a beautiful landscape from a bench at the park or something. “I was kind of hoping you’d find me here, but I don’t really feel like talking to the others right now.”

“Okay,” Bert said as he closed in. “You alright?”

“Not really. Cathy said she doesn’t think she can, uh, be with another woman.”

“I’m sure you two can work something out,” Bert tried to reassure his friend.

“I don’t think so,” the feminine figure replied with a delicate voice, choking up as she continued. “We were… trying to be… intimate, and she just… froze. The way she looked at me, you know, my body, it was clear it wasn’t going to happen. So we stopped.”

“But you’re still Mel on the inside, right?” he asked.

“I don’t know anymore,” Mel said with a strange, almost amused tone. A ripple blossomed out from where Mel was sitting. Bert leaned forward and saw bare feet teasing the surface of the liquid in the pool.

“Hey! Should you be touching that stuff again?” he asked, alarm winning out over his attempt to sound calm.

“It’s okay, it doesn’t feel like it’s doing anything this time,” Mel answered with genuine calmness, brushing a lock of hair away from the remnants of a human ear that was still in the process of being absorbed back into the side of Mel’s head. “Besides, couldn’t get any worse, right? Even if it did make the changes happen faster, might as well get it over with, you know?”

“Don’t talk like that, Mel!” Bert said. “They’re still looking for a way to change you back-”

“They’re not going to find one,” Mel interrupted. “And you have to stop trying to cheer me up about that. I’m not a child, Bert. And despite what you might think, I haven’t turned into a delicate flower that needs to be handled with care either.”

“I don’t-” he started before Mel continued.

“Yes you do. You think I can’t notice how you’ve treated me since I fell in?” Mel turned to him and gave him a kind of weary but certain look. “Because I look like a pretty girl, you’ve been acting like I need to be protected. It’s kind of admirable, but also annoying. And you don’t even know you’re doing it. But I know. I remember being one of the guys before, and now that’s not how you look at me. Gawd, at least Cathy doesn’t have that macho ‘must protect pretty girl!’ instinct going on. Trust me, having been on the other side I know how those thoughts work, and I can see them on your face every time you look at me.”

Bert was still searching for the right response when Mel changed the subject.

“You know, I’ve been reading a lot lately.” The girlish faced turned to set its purple eyes on him. “Books, I mean. Physical, paper books. Thick ones. Without any pictures, even.”

“Uh, okay?” Bert said, not sure where Mel was going with this.

“You know I’ve never been a reader, Bert. But now, suddenly it’s like someone threw a switch, and BOOM!” she threw her hands out for emphasis. “Here I am checking out War and Peace and stacking The History of Cosmology on top of The Wealth of Nations on the ‘finished’ side of my coffee table! I haven’t even looked up who won a football game in weeks, I’ve been having so much fun just sitting on the couch and reading! I never knew it was possible to just disappear into a book, Bert.”

“Are you trying to disappear, Mel?” he asked.

“Nice try, but I’ve also read the DSM five,” Mel smirked. “And no, in case you’re worried, I’m not experiencing symptoms of gender dysphoria or depression. Which is weird, right? I mean, in retrospect-”

“Retrospect?” Bert teased, trying to keep the mood light. “Did you also happen to eat a dictionary?”

“Only visually,” Mel replied. “Anyway, I may have had feelings consistent with those conditions before. Definitely the first week, I would say, but as time goes on and the changes slow down, I just… don’t.” Her tiny foot lifted out of the mysterious fluid, a few drops falling from her sole. She pulled it back slowly, then suddenly kicked outward and sent a sprinkling of the colorful liquid arching through the air until they fell back to rejoin the indoor pool, creating a line of rippling circles that grew outward across its surface.

Bert looked at her, searching her for signs of emotional conflict. He found none. His friend was calm, even relaxed. And he realized he’d been mentally referring to Mel as female for more than half of the conversation at this point.

“So, what do you think that means?” he asked. “You’re just going to accept all this?”

“Yeah,” she replied. “And I’m not sure I have a choice, really. Even if the doctors were able to find a way to stop the nanites without killing me, I think they’ve already been working on my brain and kind of, well, gotten me over the hump.”

“Your brain?” Bert asked, thrown immediately back into an alarmed state.

“I mean, they’d have to do some rewiring of my neurology just to get the tail working, wouldn’t they?” she said, flicking the silky appendage at Bert playfully. “So yeah, even before the doctors were able to find signs of them past the blood-brain barrier, it kind of stands to reason that they’d been working on my nervous system already. And it would explain the whole ‘books’ thing, as well as…” she trailed off.

“As?” Bert asked.

“I still love Cathy,” Mel said. “I’m still attracted to her. And I still find myself looking at pretty women around me, you know, the way I always have. Nothing about that has changed at all. But now there’s… more.” She looked at Bert and saw that he was waiting for her to continue. “You know what I said about that whole ‘macho must protect girl’ thing? Well… to be honest, it’s annoying. But it’s also kind of endearing.”

“Heh, yes I do have that effect on wom- uh, people,” Bert said, puffing up his chest a bit before catching himself and feeling self-conscious.

“Women, Bert. It’s okay. Actually, I’m glad you feel that way.” She tucked her legs in and spun around on the concrete wall, then dismounted and stepped closer to him. He could see the small, purple, bony nub that was starting to push through her bangs above her forehead, it seemed larger than yesterday. And her skin had a slightly more purple cast in the diffused sunlight. Cathy’s fancy stretch-top clung nicely to her compact torso and outlined the curve of her modest bust flatteringly, her bare midrift showing of a very narrow and toned waistline that flared into the considerably curvy hips hidden beneath the dark blue jeans she’d had to buy for herself because Cathy’s measurements were too different down there. She was standing on the balls of her tiny feet, as if supported by invisible stiletto heels; an unexpected aspect of the nanites’ alterations was the shortening of her calf, leaving her unable to stand with her heels flat on the ground.

Bert found himself struggling to think of this attractive girl as his long-time best friend, Mel, but everything was just so completely different about her that he couldn’t help seeing her as a new person. And he realized he was obviously gawking at her figure, so he bit his lip and turned to find something interesting in the corroded pipeworks to his left. It caught him off guard when a warm, soft body pressed against his and slender arms wrapped around his chest to lock tightly behind his back.

“Mel?” he asked, surprise evident in his tone.

“I just want to try something,” she said, laying her head on his shoulder.

Bert hesitated for a couple of seconds before slowly folding his arms around her narrow shoulders. She sighed, her body relaxing against his. He pivoted slightly to rock them gently side to side.

“You smell nice,” she said after a moment. He didn’t know how she wanted him to respond, so Bert just sighed and adjusted his embrace slightly. Then he felt her hands slide down his back and round over his butt, slipping into his back pockets. She crushed herself in closer. He felt himself hardening against her hip, but she didn’t pull away. “Mmmm. You feel nice, too,” she said.

“Mel…” he started, unsure of what to say.

She withdrew her hands and caught his as he pulled back, gently rubbing them with her slender thumbs, before guiding them to the front of her shirt and placing them squarely on her bust.

“Do I feel nice?” she asked softly, watching his face carefully. She could see the conflicting emotions playing out, but he didn’t remove his palms. Quite the opposite, in fact, and his pupils widened with palpable excitement.

“Uh, Mel… I don’t know if-”

The world spun away, Mel and then skylight rotating towards his feet as the low concrete wall rolled behind his back. He saw the colorful surface of the pool descend into his vision from above. Then he was rudely shocked by a wet splash.

She had pushed him in! And she was smiling while she did it! The realization came simultaneously with the sensation of pins and needles all over his skin as the liquid rushed into any gaps his clothing offered, covering him with its toxic fire. He had the wild conception of the stuff rushing into him like hypodermic injections through every pore, and the burning heat of its touch was like bathing in rubbing alcohol. Even the little bit that had crept into his nostrils was like a noseful of angry ants as he desperately exhaled to try and clear it while righting himself and thrashing towards the wavery image of dilapidated skylights.

His face broke through the surface and rivulets of burning chemicals streamed down his cheeks, his hair plastered to his forehead as he spun around. Mel was standing over the wall, waving. Still smiling.

“Come on out, you don’t have to marinate in it!” she chuckled, reaching out her slim arm to offer him rescue from the trap she herself had set. Desperate, he reached out and grasped her hand and closed around it like a clamp. Bracing himself against the wall with both feet and his other hand, he tried to raise himself as she reinforced her grip with her other hand and leaned back. He rose high enough to grab the ledge of the wall and secure his elbow against it, heaving himself up with a lunge. The open air was desperately sucking the vapor of the chemicals in his clothing so quickly it felt like a chilly breeze was sweeping over him, counteracting the heated sensation of his skin.

The two of them finally succeeded in pulling him back over the wall and he collapsed onto the floor, heart pounding and lungs fighting to hoard as much air as possible.

“The stuff takes away a lot of heat when it evaporates,” Mel said calmly. “We’d better get you out of those close or you’ll nearly freeze, just like I did.”

“What the hell?” he demanded as she pulled off his shoes and dumped the liquid out of them before peeling off his socks. She was right, though, he now felt like he was standing in wet clothes on a cloudy day in January. All his heat was being carried off by the mysterious chemicals, which converted to shimmering vapor billowing away from him.

“Help me with this,” she said. “Trust me, you DON’T want to stay wet long. Remember what happened when I fell in? They had to wrap me in a thermal blanket because I couldn’t understand the thermodynamics of evaporative cooling.”

“What?” Bert repeated uncomprehendingly.

“You’ll freeze if you don’t strip, so get to it,” she said authoritatively.

“When the hell did you get so nerdy?” he grumbled, but his chattering teeth told him she was right. Begrudgingly, he pulled the soaked shirt off of his body while she worked on his pants. “What’s going to happen to me?” he asked.

“The same thing that happened to me… probably,” Mel said calmly. “We’ve got about an hour until the nanites start acting on you, so-”

“WHY DID YOU DO IT?” he shouted, crawling away from her with his pants around his ankles.

“I’m lonely,” she said.

They’d frozen in place like two sculptures, only their breathing giving away the game. It seemed like the silence was going to lay between them forever until Bert sneezed. That seemed to give her permission to move, so she approached him and slipped the bunched-up pant legs from his feet. “I’m all alone in this,” she continued. “Cathy and I, we’re just not working anymore. She can’t feel the way she used to about me, even if she won’t say it. And everyone at the hospital, everyone at work, they all look at me different. Talk to me different. It’s not just the thing where suddenly they talk to me like I’m a woman, it’s more than that. They… they pity me, but they also don’t want to get close to me. Like I’m contagious. They all keep their distance. One of the doctors still wears a mask when he visits, for Pete’s sake! And I’m… I’ve started to feel… new things. Think new things. I want to try… new things.”

She was looking at his briefs when she said that last part, not even trying to conceal her intentions.

“Besides,” she continued, smiling coquettishly as if to emotionally change the subject. “It’s technically your fault.”

“My fault?” Bert asked, feeling enraged. There’s no what he would do this to his best friend on purpose, but here she was doing exactly that. He’d never meant for any of this to happen! The fall was an accident! He was just joking around, he didn’t mean for Mel to lose his balance and actually fall into the stuff… “Yeah, I guess it is, isn’t it? Geez, I’m sorry Mel.” His chest sank with a heavy sigh as he finally let himself accept the blame. “I took it way too far, and I put you in this situation. I guess it’s only fair I have to go through it with you.” The chemicals were already mostly evaporated, leaving only his hair and the pile of clothes a little damp. His skin chilled and tingling slightly.

“An apology, eh?” she said with a smirk. “Well I guess there’s hope for you yet. Now,” she said, parting his bare knees and leaning closer in with heavily lidded eyes. “Let’s talk about how you’re going to make it up to me. And remember, we only have about an hour..”