((I think I wanna marry you.))
Pinkie Pie had a problem. Her face was way too small.
Some might look at her and argue that her face was a very normal size for an average pony, which was true. But when Pinkie Pie spoke of a 'smile as wide as a mile,' she was not using hyperbole in any sense. She had at least a mile's worth of smile in her at any given time, and only one normal-sized face to try and fit it onto. Her face was far too small.
So she borrowed space on other ponies' faces. She would tell ponies jokes, and give them treats, and they would hold her smile for her, and sometimes that was almost enough to get it all out. Almost.
But today, it wasn't even close. There weren't enough faces in all of Equestria to hold Pinkie's smile today. She quivered, her hooves vibrating on the floor beneath her as she tried, without much success, to contain herself for the sake of those standing close to her.
“Beloved ponies.” Celestia's voice rang soft and clear through the vaulted gathering hall. All eyes had already been focused on the ponies at the front of the room with the Princess, but now that she had spoken up, silence passed over the crowd. You could hear a pin drop. Or rather, you could hear Pinkie's hooves clattering against the tiles as she fought to hold still.
A gentle hoof touched Pinkie's shoulder. She glanced to the side to see Rarity giving her a warm smile. Pinkie returned with an excited grin as she let her hooves relax.
Celestia beamed as she continued. “We are gathered here today to witness something truly remarkable. Unusual, yes, but then, unusual seems to follow these six around like their own shadows.”
Pinkie let out a quiet snort, and she heard the others join in with hushed giggles.
“Nevertheless,” Celestia said, shaking her head, “it is something truly wonderful we are here for today. The joining of six souls into one harmonious whole.” She spread her wings out as she said this, and Pinkie Pie could feel her cheeks aching as her smile threatened to push them clean off her face.
Celestia turned to Twilight, who looked to be wrestling with nearly as big a smile as Pinkie was. “Twilight Sparkle,” the Sun Princess said. “Once my student, forever my friend. Twilight, do you take these mares before you, to bind them to yourself, and you to them? Do you swear to guide them, to teach them and learn from them, to always illuminate your path with the magic of their companionship, for all of your life?”
Twilight nodded her head. “I do.” Pinkie could feel her smile grow wider.
Celestia smiled and turned. “Applejack,” she said.
The farm pony had a veil sewn onto the brim of her hat, through which she grinned broadly at the princess.
“Noble Applejack, do you take these mares before you, to bind them to yourself, and you to them? Do you promise to be their constant, their unyielding rock to lean on in times of need? Do you swear to let your wisdom and strength of character shine on them, for all of your life?”
“Nothin' would please me more, Princess.” Applejack tipped her head forward. Pinkie's smile grew wider still.
“Rainbow Dash,” Celestia said, turning again. “Faithful, brave Rainbow, do you take these mares before you, to bind them to yourself, and you to them? Do you swear to be forever loyal to them, to protect them in body and mind and soul, for all of your life?”
Rainbow Dash's grin made Pinkie's heart skip. “I do, Princess.”
“Fluttershy.”
The yellow pegasus looked up at the Princess steadily. There was no trace of fear or nervousness in her turquoise eyes.
“Gentle Fluttershy, do you take these mares before you, to bind them to yourself, and you to them? Do you swear to care for them, to love them always and to be loved by them in turn? Do you promise to be a beacon of warmth and kindness for them, for all of your life?”
“I do.” Pinkie could not imagine her smile growing any wider than it already was, but somehow it did.
Celestia nodded and turned once more. “Rarity...”
“I do!” Rarity covered her mouth with a hoof, her cheeks flushing bright red. She coughed into her hoof. “I—I'm sorry, please, go on.”
Celestia covered up a soft giggle. “Rarity, do you take these mares before you, to bind them to yourself, and you to them? Do you swear to give freely of yourself to them, without hesitation nor condition? Do you promise to sacrifice yourself for their happiness, knowing that they will do the same for you, for all of your life?”
“Yes, your highness, I do.” Pinkie Pie's smile hurt. It was too much to contain.
“Pinkamena Pie,” Celestia said, at last facing her. “Sweet Pinkie, do you take these mares before you, to bind them to yourself, and you to them? Do you swear to always share you happiness with them, to give them your smiles and your laughter? Do you promise to lift their spirits in their darkest times, and keep them up in their times of triumph? Do you swear that your happiness and their happiness will be one in the same, for all of your life?”
Pinkie Pie's smile was more than she could bear. She took it, like it was a physical thing that could be molded and manipulated. She mushed it up and re-formed it until instead of a smile, it was two tiny words. Two little words that meant the world to Pinkie, words that she had been waiting all day—no, much longer than that—to say. Two little words that were the only possible container to keep her smile in.
“I do.”