Twilight Sparkle was undoubtedly the worst dancer in Equestria, and everypony but Twilight knew it. At social gatherings, it was an unspoken rule to always keep a few paces away from the newest princess, or else risk being smacked in the jaw by a flailing limb. The few dignitaries and visiting ambassadors who didn't quite get the warning in time were usually smacked by Twilight's uncoordinated movements, which more or less exactly failed to be graceful.
It made sense, therefore, to assume that nopony would ever want to dance with the mare. She trodded on hooves by mistake, stumbled over dress edges and tore hems, and bumped into quite a few important rumps as it was, and that was without a partner. It was only logical that, while Twilight could be counted on to hold her own in a political debate or diplomatic discussion, no pony would offer to dance alongside her in what most would consider an undignified insult to the form and flow of an ancient form of expression.
With all this in mind, one can only assume that it came as quite a shock when Rainbow Dash, official Wonderbolt extraordinaire, asked Twilight Sparkle to dance at the Grand Galloping Gala.
And nopony was more surprised than Rainbow Dash herself. She hadn't meant to blurt it out all of a sudden, and, truth be told, her proposition had sounded a lot wittier and subtly tactful when she had rehearsed it in her mind for the previous half an hour. Sweet Celestia, she hadn't actually shouted it, had she? Rainbow certainly hoped not, but an awful lot of ponies had turned to gape in horror at her request.
To a few ponies’ surprise, Twilight Sparkle immediately accepted, in a hurried and somewhat flustered tone she must have saved for this very occasion. Rainbow stared at her uncomprehendingly, so Twilight repeated her answer. The second attempt seemed to reach the few brain cells in Rainbow's mind that weren't trying to figure out how to backpedal from the whole situation. She smiled weakly at Twilight and looked around, still partially wondering if she was going to go through with the whole thing. Ponies were staring, and most of them looked moderately important.
The onlookers would remember her decision, Rainbow realized. She could give into anxiety and fly away in a particularly unstealthy blur of colors and light, or she could own up to her moment of courage, and dance with the most graceless mare in Equestria. Both, in their own way, were unthinkable to most. Rainbow Dash was only beginning to understand the twisted world of high class social events, but even she knew that backing out was the far worse option. Much to the horror of those watching, Rainbow nodded once, twice, and spoke. “Well, then,” said the flustered pegasus. “Let’s get to it.” She held out her hoof with as much dignity as she could muster. Twilight wrapped both of hers around it, clinging to it as though it were a lifeline.
Flabbergasted, the onlookers watched as Rainbow took Twilight's hoof and lead her onto the dance floor. Ponies cleared the way, staring slack-jawed as one would if their house were being swallowed by a vengeful tornado in the middle of an afternoon picnic. They surrounded the couple, both of whom were just then realizing that neither of them knew how to dance in a pair.
But it was much too late for hesitation, and the music swelled, billowing over the ballroom in sweet saccharine tones. Taking one hoofstep, then another, Rainbow guided Twilight in what a preschool teacher would call nearly a circle. The ponies watching held their breath. The location, the dresses, the scenery… it was almost magical, like something from a fairy tale. All eye were on what many would agree later were the most beautiful mares at the Gala.
Then, Twilight began to move her front hooves, kicking out with one of her hind legs. A few members of the crowd flinched, but neither Twilight nor Rainbow noticed. Slowly, wobbly, Rainbow Dash mirrored Twilight's movements, lifting her legs up one by one. Awkwardly, they began a slow shuffle that perfectly clashed with the rhythm of the slow, sensual purr of the waltz filling the ballroom.
Back and forth they swayed, picking up speed gradually. The crowd stepped back, giving the gyrating, swiveling mares more space to flail in harmony. They moved with no grace, no charm, no discernable flourishes. Rainbow surveyed the crowd. Were they judging here? Perhaps she should slowly dance her way out of the situation.
But then, Rainbow’s gaze shifted to Twilight. She was beaming. Her eyes were wide open, and the colors and lights of the ballroom reflected back at Rainbow. It was the most beautiful sight Rainbow had ever seen, and she had seen the sun rise through the waterfall rainbows of Cloudsdale. Rainbow laughed. Maybe this wasn’t so bad, after all?
What had she even been dreading? The watchful, judging gazes of the ponies faded away into a chromatic blur as the two mares circled. The music picked up slightly, but Rainbow hardly notice over the sound of Twilight laughing back. Wow, Twilight was having the time of her life! Rainbow smiled, a great big goofy smile, hardly noticing how they spiralled closer.
It didn’t seem to matter if Twilight was bad at dancing. In fact, if Twilight had suddenly become the most graceful waltzer in Equestria, Rainbow wouldn’t have noticed. She couldn’t tear her gaze away from Twilight’s eyes, and Twilight’s smile, and Twilight’s joy that shone from her like the sun through a stormcloud.
Closer and closer they danced, narrowly missing each other with extended hooves and flared wings as they circled each other. Even the swells and sweeps of the music faded away, drowned out by the blissful laughter of the two mares. First their hooves met, brushing against one another, their fur tingling with the sensation of another’s. Then they clasped hooves and began twirling, around and around. Wings jutted out and brushed against feathers and silken dresses, tails swished and tangled in sequins, and hind hooves kicked out and shook. Neither mare noticed.
The roaring of Rainbow’s heartbeat snapped her out of it for a moment. Gosh, Twilight’s muzzle was closer than it had been. And Twilight’s eyes were half shut. The music had probably stopped at one point, because all Rainbow could hear was her heart racing and the sound of two mares panting slightly. This was an opportunity. This was something that other ponies would talk about for months, no matter what the outcome. A princess and a Wonderbolt, practically the juiciest piece of gossip anypony would hear in a lifetime. Rainbow knew she’d never hear the end of it in the locker room.
And then Rainbow realized she didn’t care about what they’d think, and she kissed Twilight. Ponies probably gasped, cameras probably flashed, Spitfire would probably give Rainbow another lecture on how her behavior reflected on the team, but none of that mattered, because Twilight was kissing her back.