An Aquatic Fusion for Three

by Mystic Sunrise

Rating: everyone
Tags: Slice of Life, Twilight Sparkle, My Little Pony: Friendship is Magic, Alternate Universe, Silverstream, Romance, My Little Pony: The Movie, Princess Skystar
Length: 2390

Twilight finds a way to take her relationship with Skystar and Silverstream to a new level.

When she is taken far from Seaquestria one day by her girlfriends, Twilight isn't sure what to make of it. Especially when they say they want to share something with her.

Something only the two of them seems to know.

What follows will change Twilight's relationship with Silverstream and Skystar forever. Who knew fusions were so fun?

***

Again, this is not a sequel. Just a mid-story arc I made its own story. The main story would bog down if I put this there.

Published 2019-12-10 02:20:01 UTC
Last updated 2020-05-12 04:32:33 UTC

Chapter 1

Twilight wasn't sure why Skystar and Silverstream were so excited as they pulled her away from Seaquestria and out into the deeper waters. She could already see the Kraken's Trench in the distance.

"Where are you two taking me anyway? I can swim fine on my own, thank you very much," she finally grumbled.

Skystar giggled. "We're going someplace a little more private. This is just for us. Everypony else will find out later. Plus it's more fun this way."

Twilight's brow raised. "Doing what? Where are we going? Are we going back to the Trench?"

Silverstream shook her head as they began to slow down. "Nope. We just needed to get away from everyone for a while, and this is pretty far out from anywhere."

Twilight gave her a look. "Why is this so important? What am I missing?"

That finally seemed to do it for them for the three of them came to a halt at last. As they did, both Silverstream and Skystar turned to Twilight, wide grins on their faces at something. One Twilight couldn't help but return.

"We wanted to share this with you Twilight," Skystar began as she and Silverstream smiled at each other. "There's something the two of us share, something very rare in seaponies."

Twilight was interested now. "What's that?"

Silverstream's grin grew wider if possible. "We don't know if it has a name or not, but for as long as we can remember, Sky and I have an ability to get extra close to each other."

"How close?" Twilight asked.

Skystar's grin grew as well as she slid up next to Silverstream. "Really close. And we were hoping, you'd like to join us? It's something we've hoped for. That we can share it with another."

Twilight was still lost. It did sound interesting for sure, but what exactly was it? The idea of getting closer to both of them was something she wanted of course, but what would she even do? "What do I even do?" She asked.

Silverstream and Skystar shared a knowing look before, as one, swimming over to Twilight's left side and wrapped their tails around her own. "Just relax and let your necklace connect with ours," they said together.

Silverstream looked at Twilight with a serious expression. "Do you trust us?"

Twilight didn't hesitate as she leaned her head on Silverstream's shoulder. "I trust you," she whispered.

All three smiled together as they leaned their heads together. As they did, they felt their necklaces connect in a way that felt strange to Twilight. Yet it felt right all the same.

As the feeling grew, Twilight felt her body begin to change. In fact, it felt like she was merging with Silverstream. But that didn't make any sense. Did it? Even as the thought crossed her mind, she felt the feeling in the left side of her body vanish. She knew it was still there of course, but she could no longer feel it at all.

It didn't feel wrong though, she thought, as the process continued. In fact, it felt right. Maybe this was normal for Skystar and Silverstream as well?

For a time this went off. As it did, all three of them began to glow, so much so that Twilight was forced to close her eyes against the brightness of it. But even though she had, she could still feel it when the process stopped. Not with a lurch or thud as she had thought it might, but it just suddenly, stopped all on its own.

Silverstream giggled. "You can look now Twilight. It worked."

Twilight opened her eyes and looked at her. "What worked?"

Silverstream just looked down. Twilight did the same and felt her mouth drop in shock at what she saw had happened to the three of them.

Her body, along with Silverstream's and Skystar's, had been merged into one. Their now shared body bore all three of their colors. Skystar's on their left, Silverstream in their middle, and Twilights on their right. Their tail was a combination of Silverstream's and Twilight's own it seemed.

Twilight tried to flick it with no luck. But she could still feel her tail. How did that even work?

Skystar giggled from Silverstream's left. "It's a team effort Twilight. I felt that flick of our tail you tried. Heck, I can feel you all the way over here. Can you feel me?"

Twilight concentrated for a moment. She could, in fact, feel Skystar. Rather intimately too. The same went for Silverstream. Maybe that was normal for this? "So how does all of this work? I don't like the idea of not having control over my own body. Or at least part of it."

Silverstream nodded. "You can still use your hoof. We all just shared everything else. Or if we really wanted to, we could share everything about our body."

Twilight wanted to see that for sure. But first, she tried moving her hoof. To her relief, it moved just like normal. That put her mind at ease about that at least. She also wondered what the three of them could do like this? And how long would it last?

And did she even want it to end? She pushed that thought aside for now. It was far too soon to even think about something like that. She still had a lot of questions though. "Are we the only ones who can do this?" She asked.

Skystar shook her head. "No. There's another trio that can do what we do. They've actually been doing this a lot longer than we have. Longer than we've been alive in fact."

Twilight blinked. "How come I've never seen them?"

Skystar and Silverstream shared a look. "They don't come out much. No one makes them hide or attacks them. But they've given in to a side effect of doing this for so long," Silverstream replied.

Now Twilight was concerned as she frowned. "What side effect?"

Silverstream sighed. "They've spent so much time together like this, that they refuse to leave each other's sides, no matter what. And all three of them are different ages. And they're not family. It's something that makes them stick out in a crowd. It's scared the youngest so much it's gone to her companions as well."

Twilight didn't understand any of this. "But Queen Novo-"

"There's only so much mom can do Twilight. Even she can't fully help them with this. And she's tried. The best she can do for them now is to try and make their eternity as fun as it can be," Skystar interrupted.

Silverstream nodded. "It's another side effect. They're bond, and being different ages, has made them immortal. They haven't aged a day in over a century."

Twilight's ears fell as she tried to process this. That wasn't fair at all to those three, and even though she didn't know them, she felt her heartbreak for them. "Are they nice?" She asked.

Skystar nodded. "They're three of the nicest seaponies you'll ever meet. I and Silvy are friends with all of them. And with us now like we are, I can't see why they wouldn't want to meet you too Twilight."

That helped ease Twilight's fears quite a bit, and she looked forward to meeting these three at some point. But right now, she wanted to see what the three of them could do like this.

Author's Note

Just another crazy idea I had that would not leave me alone. So here it is. This is fully canon with Under the Sea, but there will be no spoilers for the main story.

When this takes place in the context of the main story is open to whatever you want. But it is after Twilight's trip to the Heart Of the Sea. That's it though really.

Chapter 2

As the three of them floated there, silent for a time after explaining to Twilight as much as was known for what was going on with them at the moment, Silverstream let her mind wander.

It was unusual for her to be the center head in the fusion. When it had just been her and Sksytar, it had never felt weird or been a problem since it had only been the two of them.

The first time it had happened to them, it had freaked both of them out. They both knew of Wave Crest, Ocean Breeze, and Sea Spray. All of Seaquestria knew the three of them and what they could do.

It had been the three of them that had helped her and Skystar adjust to their new bodies when they fused together, and it had been Wave Crest who had helped them learn how to switch around where they sat.

So while Skystar usually was the middle head in these times, Silverstream had more than often been in her place as well. The effect wasn't any different, no matter who was where. But she thought so at least.

Maybe it was just because she was slightly eccentric, as most residents of the kingdom would tell anyone who asked, but Silverstream enjoyed her time like this. In fact, she missed it more and more it seemed every time they pulled apart.

Now with Twilight fused with them as well, that feeling had only grown, and a growing part of her didn't want it to stop. She didn't say it out loud of course. She wasn't that crazy. Usually.

But the feeling was there nonetheless. Silverstream could feel their entire body like it was her own. She could feel their individual Pearl Necklaces like they were her own as well, and she knew for a fact that wasn't normal.

Normally, only the seapony who wore the necklace would ever feel its power within them. Everyone else would just feel the necklace itself and that was it. No one really knew if more was possible.

Maybe Wave Crest, Ocean Breeze, and Sea Spray knew more about it, but they rarely ever spoke of what it was like for the three of them in this form. The basics were known to all of course.

But the mental effects were less well known. It did seem like the other two always bowed to Sea Spray, in and out of their combined form, but that was strange simply for the fact that Sea Spray was the youngest of the trio by a long way.

Heck, she was even younger than she, Twilight, and Skystar were. Even accounting for the fact that she hadn't aged for over a century, if Queen Novo was right, Sea Spray looked like a young filly, and still held some of the same manners and thoughts of someone her age.

It was strange, to say the least. That aside though, she was also one of the nicest ponies in Seaquestria. Both Silverstream and Skystar considered her a friend, maybe even more than the other two.

Not that they would ever tell them that of course.

***

For Skystar, while she was used to being the second head while in this fusion with her cousin, with Twilight now apart of them as well, it was a whole new experience for her. The same probably holds true for Silverstream as well.

This whole ability was still odd to her, even though they'd had and known about it for years at this point. Even with her position in the kingdom, and who her mother was, Systar still didn't fully understand all of this.

Mom herself didn't know much more than she and Silverstream did either, and it vexed her to no end, Skystar knew that as a fact. She'd heard it often enough not to question it.

What worried Skystar though, was Twilight. She seemed to be taking all of this rather well all things considered. But there was another side effect of their fusion into this form, one they could all do by themselves if they put their mind to it.

Skystar could feel Twilight's confusion as to what had happened to the three of them, and even deeper than that. Her fear of what it could mean if they remained like this too long. Something that she could not blame the mare for.

Skystar and Silverstream had known about this for years at this point. They were even comfortable in doing this, and staying like this for as long as they could without losing themselves and never wanting to be separated again.

Twilight though was another story altogether. Neither of them had even known if they could do this with her in the beginning. While both of them were happy they could to be sure, both girls were worried about their new companion.

For the moment at least, none of them felt any different, and that was a small miracle at least.

***

While Silverstream and Skystar seemed to be deep in their own thoughts, Twilight's own mind was all over the place. She was slowly getting used to being like this, and she was even enjoying it with each passing moment.

It wasn't that she didn't trust either of the girls next to her of course. She trusted them entirely, and that trust had only grown once they had come together as they had.

It was obvious neither Skystar or Silverstream had known what would happen when they had asked Twilight to do this with them. She didn't have to read minds to know that. She could feel it in their shared body. How Silverstream's fin would brush up against Twilight's own.

It didn't take much effort to put two and two together. They were worried about her, and while Twilight appreciated their concern, she was fine, thank you very much. She could handle herself. Didn't they know that? She had proved it several times already before all of this.

But a part of her knew why they were worried about her. She was still new to all of this, and she was still growing into her new role and life. Of course, her best friends would worry about her.

This though was proving to be a great way to help beat back some of Twilight's own worries. Worries that she tried not to think about as she once again lay her head on Silverstream's shoulder.