Graph Theory

by stillinbeta


1 - Graph Theory

With a now very familiar feeling of nausea, Princess Twilight stepped out of the portal and onto the grounds of Canterlot High. Somehow the trip got worse every time she passed through. She really needed to talk to someone about that.

“Hiya Princess.” Sunset Shimmer was sitting on the steps leading up Canterlot High.

Someone like Sunset, maybe.

A theory about parallel worlds and subatomic particles was on the tip of her tongue. Unfortunately, her stomach chose that moment to do the internal organ equivalent of a sonic rainboom was. In response she doubled over, clutching her midsection.

Sunset rushed over to help.

A yellow hand offered her something. “Easy now. Here, drink this.”

Twilight took a sip from what appeared to be a bottle of soda. Her stomach appeased for the moment, she slowly rose. Her hand flattened out her skirt as she stood.

“Do you think that —” Twilight began.

“That it's getting worse?” Sunset offered. “I have a theory about that actually...”

The two girls made their way, one a bit unsteadily, in the general direction of the bus stop across the street. Once there, Sunset handed Twilight a couple of crumpled bills for bus fare.

A lull in conversation left both of them staring idly at the school.

“How’s Equestria?” Sunset’s eyes lingered on the long-replaced statue.

Twilight looked over at her. Sunset’s expression was unreadable.

“No crises this week, thankfully. My Pinkie actually threw a ‘Nothing’s Tried To Destroy The Town In Over A Week’ party, which really seems like tempting fate.”

It used to make Twilight uncomfortable calling her friends “My Pinkie” or “My Applejack,” since they were certainly not hers. So far, though, it was the best convention anyone could come up with. “Pony Rainbow Dash” was too unwieldy, and “Universe B Fluttershy” led to a spat about which was “Universe A.” So “Twilight’s” friends they were.

Twilight continued.“They all send their regards, by the way. Well, Rarity sends her ‘regards.’”

Twilight tried making finger quotes for “regards,” but just ended up waving her hands. Hands were tricky.

“Applejack sends a ‘howdy,’ Fluttershy said ‘hi,’ and Pinkie just giggled like she knew something I didn’t. Oh, and Rainbow Dash was asleep when I left.”

Sunset was giving her a much more readable look, and burst out laughing at the end of her spiel.

“Glad to hear it, Princess. Sounded like you could use a break.”

“Princess,” a nickname Twilight would never have let “her” friends use, was another conceit to interdimensional travel. She was a princess, her science-obsessed counterpart here wasn’t, so Princess she was. Really, it made everything less confusing. It was fine.

“Yeah, no kidding. Just running my little corner of Equestrian government is a challenge on a quiet day. Even when there’s no monsters or magical coups it’s hard to call any day ‘quiet.’”

Sunset nodded knowingly. “I was gonna complain about my Ecology term paper, but compared to running the government of a country, it seems kinda silly.”

“Oh, no! I didn’t mean to imply... You’re my friend, and I want to hear what’s up in your life.” A sly smile crossed Twilight’s face. “Speaking of, how are things with you and Fluttershy?”

Twilight didn’t really need an answer after that. The way Sunset’s face lit up told her everything that she needed to know, but Sunset answered anyway.

“It’s been... really nice. I know that’s not a very descriptive adjective, but that’s how it feels. We get dinner together, watch a movie, and just like... cuddle. It’s cozy.”

Sunset wasn’t just beaming now, she was blushing. Twilight couldn’t help but smile at her friend’s lovestruck expression.

“That does sound... nice.”

“I still don’t understand how I got this lucky. I was horrible to the poor girl, bullied her, and tore her apart from her friends. And now she’s got a toothbrush in my apartment.”

Twilight thought about saying something snarky about the toothbrush, but it didn’t seem appropriate at the moment. She went in for a hug instead.

“Sunset, you need to stop beating yourself up over that. We’ve all done some things we’re not proud of, but you’ve done your penance. Your Fluttershy trusts you completely and, your relationship proves that.”

Sunset squeezed Twilight, then pulled back and looked her in the eyes.

“I know, Twilight. And it’s all thanks to you. If you hadn’t shown up and gotten the girls back together... I wasn’t happy back then. I didn’t even know I could be this happy.”

“I was happy to help you, Sunset. You weren’t a bad person. You just needed a little help. Anyone would’ve done it.”

“I don’t think anyone else could’ve done it, Twilight. You did what nobody in either of our worlds could do. You saved me from myself."

Twilight was suddenly aware of how close they were. She could smell Sunset's perfume, hear the soft crinkle of her jacket. Their eyes met and Twilight was frozen, a biped caught in the headlights.

“Twilight... can... can I kiss you?”

That broke the spell pretty quickly.

“WHAT?!” Twilight bellowed. “How could you even... We were just...Why would you even say that?”

Twilight expected Sunset to be remorseful or angry but instead she just seemed confused.

“What are you —”

The bus picked that moment to arrive. Twilight gave serious thought to just running back to the portal, but in all likelihood Spike or Starlight had closed it by now. The only way to contact them would be through the other journal, which was of course in Sunset’s possession.

So, one way or another, she was going to spend the night in this world, and Sunset’s couch was a lot nicer than a stack of library books.

And of course, Sunset was still her friend. Probably. She’d get an explanation, she owed Sunset that much at least.

The bus doors creaked open and Sunset boarded, flashing a shiny piece of plastic at the driver. Twilight followed behind and with a little difficulty, fed her bills into a machine next to the driver.

They pushed their way to the back of the bus to a pair of miraculously empty seats. They sat in silence for several minutes, staring out the window. The scenery here was weird. It didn’t look anything like Ponyville, but somehow felt like it. Sunset had mentioned something about “Art Noveau” at some point, but Twilight just chalked it up to the weirdness of the portal.

Twilight was the first to speak. “Sunset, how could you even say something like that? You were just talking about how happy you were with Fluttershy and now you want to cheat on her? How could you do that to her? How could you do that to me?

“What do you mean, cheat on? Nobody’s saying...” A glimmer of recognition flashed on Sunset’s face. “You think we’re monogamous!”

Twilight blinked. “Monoga-what?”

“Monogamous. Like, when two people only date each other?”

“So... a relationship?”

“Is this really not a thing in Equestria? Twilight, Fluttershy and I aren’t just dating each other.”

“Sunset you’re from Equestria, same as me. You know full well what is and isn’t a ‘thing.’” The finger quotes went better this time.

“I wasn’t exactly thinking about romance back when I lived with Celestia, Twilight. I was too busy studying, or making terrible decisions about power and glory. How much dating did you do when you lived in the castle?”

“None, but... Hey! Stop trying to change the subject! What’s going on here?”

Sunset stood and pulled the stop cord, looking deep in thought. When the bus came to a stop, she and Twilight walked silently out. The two walked in silence for a block or two towards Sunset’s apartment

Finally, Sunset broke the silence.

“The simplest explanation is probably best. Twilight, Fluttershy and I aren’t just dating each other. She’s sleeping over at Rainbow’s tonight.”

Twilight’s eyes narrowed. “So what? We have sleepovers all the time. We had one the first time I came here!”

Sunset rubbed her temples. “No like... they’re going to be sleeping in the same bed. They’re probably kissing right now. Maybe even —”

Twilight cut her off, face hot. “Okay, okay, not just a sleep over. Got it.”

Sunset grinned and nodded.

She got out her keys and unlocked the door to her apartment building. The two walked across the sad-looking lobby to the elevator.

Twilight had never noticed how small the elevator was. Had it always been this cramped? Had she always had to get this close to Sunset? Had her perfume always smelled this good?

“So, are you and your Rainbow, you know... sleeping over? Is it like a three person thing? Would I have to date your Fluttershy?”

“Do you want to? I have it on good authority that she thinks you’re pretty cute.”

Twilight blushed again.

Was it possible to die of blushing? All that blood had to come from somewhere, right? Didn’t wherever it came from need it? Maybe her heart would just send all of it to her face and she’d pass out. That way she could stop thinking about kissing a shy pink-maned pegasus. Or pink-haired girl. Either way. Any time would be good.

Sunset was laughing again. “The look on your face, Princess. I’m just teasing. Not lying, but still teasing. You don’t have to date anyone. We’re not... what’s the word... polyfidelitous.”

Twilight stopped blushing long enough to raise an eyebrow.

“If you barely know the word, I don’t know why you think I might.”

“Sorry, sorry. It’s just so rare I actually have something to teach you! Usually it’s the other way around. Let me have my fun!”

Twilight glared at her, but motioned for her to continue.

“Polyfidelitous means a set of people —” she looked at Twilight “— or ponies, who date each other exclusively. Like a monogamous couple, but with three members. Or more.”

“And that’s not what you and Fluttershy are?”

“No. For one thing, I’m not daing Rainbow. She and I went out a few times but neither of us were really feeling it. We do still cuddle once in awhile, though,” Sunset whispered conspiratorially. “She puts on a tough act but she’s a real softie when it’s just us.”

Twilight had so little an idea of what to do with this information that her brain just stopped for several seconds. Sunset started to look a bit concerned, but Twilight managed to pull herself back together.

“Okay. So you’re dating Fluttershy, Fluttershy’s dating Rainbow. And you and Rainbow are...”

“Snuggle buddies,” Sunset supplied.

“Sure, that,” Twilight said in a way that made it obvious she was not sure of anything. “Anything else I should know?”

“Well, Rainbow and Applejack have been together for over a year, and --”

“What.”

“That’s not even mentioning all the ‘special parties’ Pinkie throws.”

“Wait, so all of you girls are...” Twilight was a very interesting combination of in awe, baffled, and very thoroughly confused.

“Sleeping together? Pretty much. Rarity swears to the stars that she’s straight, but she’ll jump on Rainbow if you get a drop of alcohol in her. Literally, actually. My Twilight did a study. There was, uh, ‘titration,’ I think she called it.”

At this point, Twilight and Sunset were sitting on the couch together. Twilight took this opportunity to slowly slide off the couch and onto the floor.

“Why do you think we all hang out together, Princess? Everyone at Canterlot High had a clique. The athletes, the dramas, the eco-geeks... and the queers.”

“Huh.” Twilight was very good at assimilating information but this was starting to test her considerable limits.

“Here, why don’t I draw you a graph.”

Twilight perked up. “I think that’d help.”

“I thought it might.”

Sunset walked to her desk and retrieved some notebook paper and a few markers. Twilight expected a quick sketch, but instead Sunset got out her phone and started texting people. She was apparently pretty surprised by some of the responses because a line or two was  scribbled out, and some new ones added reluctantly. At one point she seemed to give up entirely and got out a clean sheet of paper.  Her work was transferred to this, carefully copied line by line.

“Okay, I think this is accurate.”

Twilight, made her way to Sunset’s desk and looked at the chart. It was extremely colourful. It wasn’t just the seven girls she expected, either. Flash’s addition wasn’t too much of a surprise. Trixie, however, certainly was. And seeing her human counterpart so well-connected was quite the shock.

“Okay, so green is currently dating, grey is a past relationship, blue is a hook-up...”

Twilight consulted the chart again. “Wow, Pinkie’s been busy, huh?”

“The life of every party! Unsurprisingly she’s a really great kisser.”

“What’s this black line with the arrow?”

“Uhh...” Now it was Sunset’s turn to blush. “I wouldn’t worry about that right now.”

“Um, okay...”

“ANYWAY,” Sunset announced. “I hope this clears stuff up a little. I love Fluttershy to bits and I’d never do anything to hurt her. In fact, she’s actually cheering me on.”

Sunset held up her phone, showing off a text from Fluttershy which just said, “yay.”

Twilight smiled. The more things changed...

“I’m really sorry that I asked you out of nowhere, Princess. I guess I’ve kind of gone native here. I’ve forgotten that there’s usually a bit more romantic lead up outside of my little world.”

“It’s okay, Sunset. I’m sorry I overreacted. I should’ve known you’d never hurt Fluttershy. Can you forgive me?”

Sunset smiled. “I think I can find it in my heart if you can.”

Twilight’s stomach started to feel like she’d just come back through the portal again.

“I’m still pretty confused, though. I haven’t even... really thought about romance. Let alone with you!” Her eyes widened. “N-not that there’s something wrong with you! You’re very pretty, I think! And a really good friend! I just... I don’t know!”

“Breathe, Princess. This isn’t a test. There’s no right answer. But if I might make a suggestion?”

Twilight stared at the ceiling. “A suggestion sounds pretty good right now.”
“First, a couple deep breathes.”

“Right.”

Twilight did her best to calm her panicked breathing.

Sunset smiled. “Let’s just... do dinner sometime. No commitment, no pressure. If you’re not feeling it, we go back to doing movie night just like we did before.”

“That actually sounds really nice, Sunset.”

Twilight finally managed to look back at the girl sitting next to her.

In a fit of courage, her hand crawled over the couch and found Sunset’s.

Both of them blushed, smiled, maybe giggled a little awkwardly.

“Is... is this okay?” Twilight asked.

Her voice quivered with a combination of anxiety and excitement.

“It’s better than okay, Princess. It’s... nice.”

Now they were both grinning like idiots.

“So. About that dinner?”

“About that dinner. My dimension or yours?”