This is basically a ripoff of a sequel I meant to write to an old Kunzite/Zoisite fic of mine over a decade ago. Only with ponies.
Dear Rarity,
I...I don't quite now how to say this, even in writing. I'm sorry if this is a bother to you, too, I know how busy you are and that you might not have time to sit down and read such a silly thing. But...here goes.
We've been close for a long time now, haven't we? I mean...we've been through a lot of exciting and scary things together, we have our spa days every week and you're always here for me when I need you. I...I think you're really beautiful and elegant, you have so much style and grace and to top it off you're so generous. I...I still feel as though I never properly thanked you for my beautiful Gala dress. (Speaking of which, I'm so so sorry I was such a pain about it and made it so difficult for you! I should have never been so ungrateful when you were doing me a favor! Oh, but I'm going off the subject, I'm sorry...)
Ah, I...I guess what I'm trying to say is that...there's nopony I admire and respect more than you, Rarity, and I'm so grateful that you're my friend, even when I'm being a spineless doormat. Just being near you makes me happy.
Oh, this is so hard! Twilight told me I should just write this down-oh, no, I shouldn't have mentioned her, then you'll know that she knows how I feel about you before I told you! Oh, this is turning into such a mess!
Rarity, I...
I love you. I have ever since we beat Discord and I remembered just how much all of you meant to me, but especially you. It's why I kept that modeling job even when I hated it. Why I'm so sorry about the dress business, why I love being with you so much lately.
I'm sorry, I'm sure you never wanted to hear that from me, you could have your pick of anypony, so I'll understand if you reject me.
But even if you do my feelings won't change.
And I'm sorry this turned out longer than it should have, I didn't mean to ramble on so and waste your time.
Sincerely,
Fluttershy
She folded the letter and slid it into her saddlebag. There. She'd written her feelings down just like Twilight had said to...but that didn't mean she had to send the letter to Rarity. On the contrary, if Rarity knew how she felt, Fluttershy would just die of embarrassment!
Besides, Rarity would never return her feelings. Why set herself up for heartbreak?
Fluttershy sighed as she reluctantly left her treehouse. All she wanted to do was stay in and be with her animal friends today, but there was a scheduled storm for later and if she was going to do her errands, she might as well do them now.
-x-
Fortunately, the marketplace wasn't very crowded today and she managed to find everything she needed in moments. Everypony else seemed to have other plans that day, which suited Fluttershy just fine. Today was the sort of day to sit at home with her animals, maybe have a cup of tea and read a good-
"Aaiie!" Not paying attention to her surroundings, she'd crashed into somepony, the contents of her saddlebag spilling onto the ground. "Oh, I'm so sorry! I should have been watching where I was going, I-"
"Fluttershy?"
Oh no. The one pony she'd been hoping to avoid. Rarity's concerned, surprised eyes looked into hers and Fluttershy wished she could just disappear.
"Oh...h-hello, Rarity. I thought you'd be busy in the boutique today," she stammered. "I'm so sorry for getting in your way, I-"
"Please, darling, it was hardly your fault," Rarity assured her. "I was the one who should have watched where I was going, I was in such a rush to get my fabric...and look, I've spilled your belongings everywhere! Please, allow me to help you gather them."
"Um, you really don't have to, Rarity, I..." But the unicorn was already busy at work. Fluttershy sighed and began to pick up some of the spilled items as well, the sooner everything was back in her bag the sooner she could make a graceful exit and go back home.
"Oh? Whatever is this?" And Fluttershy's stomach flip-flopped, realizing what Rarity had just picked up. "Something addressed to me?" No! She must have been so distracted earlier that she'd folded it inside out, how could anyone do something so stupid?
"Um, Rarity, it's nothing, it's just something I-" She made a weak grab for it but Rarity was already reading it. Nonononono-!
It was over. It was all over.
-x-
Oh...oh my!
Rarity gasped as she read the letter carefully. Shocked as she was by this revalation, a part of her wondered how she'd missed all the signs. Those admiring looks, the constant efforts to spend time together, those meaningful smiles, her compliments! Why, she'd been more obvious than dear little Spike when she really thought about it.
As Rarity finally reached the end of the letter, the realization sank in that she felt the same way. Oh, Fluttershy! And to think all this time she's been suffering in fear that I may reject her! How could I not have realized it sooner? If only I'd known! But she wasn't going to let herself feel guilty, not right now. Fluttershy was right in front of her, so the only thing to do was confess her feelings. A grand declaration of love that would bring tears to the eyes of all who saw, smiles to their faces, applause from Princess Celestia as she watched over them with approval!
But before she could open her mouth, Fluttershy shook her head, squeaked out a barely-audible apology and flew off in tears, leaving her saddlebag behind.
"-Fluttershy?" Rarity sighed, folding the letter and sliding it into her own saddlebag. "Well, that didn't work out quite the way I'd hoped."
With as much grace as she could muster, she gathered Fluttershy's saddlebag and hefted it over her other side, then made her way to the other's treehouse as fast as she could.
-x-
She made it back in record time, or at least record time considering she was carrying two rather heavy saddlebags. Tonight I'm going to take the longest, warmest bath, she thought as she knocked at the door.
"Fluttershy? Please, open up...we need to talk."
It seemed like forever until she finally heard hoofsteps approaching, followed by the door slowly opening to reveal a red-eyed, sniffling Fluttershy. Oh, Celestia... The sight broke Rarity's heart.
"I didn't think you'd want to talk to me after reading that," she said quietly. "Oh, Rarity, you must be so uncomfortable! I wouldn't blame you if you never wanted to see me again..." Oh, how Rarity wanted to fling open the door and sweep Fluttershy off her hooves right then and there! But this was a very delicate matter and Fluttershy was so sensitive, a gesture like that would only frighten her.
"May I come in and sit down, please?" Fluttershy was still for a long moment before giving her a small nod, opening the door wider so Rarity could enter and set the bags down. They sat down at opposite ends of the sofa, a long silence following before Fluttershy finally cleared her throat and spoke.
"I'm sorry."
"Fluttershy," Rarity said, "what exactly are you apologizing for?"
"Everything," the pegasus said quietly. "For writing that silly letter, for bothering you with it, for running away...you must think I'm the most awful pony." She looked ready to burst into tears again and Rarity knew she had to pick her next words carefully. Tentatively, she moved closer to Fluttershy, placing her hoof against the other's.
"If I were to be upset about anything, it would be none of the above," she said. "Only that you weren't more honest with me. Fluttershy, we've known each other long enough know that you should no longer be afraid to share your feelings! The fact that you've been hiding for so long and immediately assumed the worst upon my finding out...well, I can't help but feel as if I've failed you." Well, perhaps that was a bit of an overdramatic way to put it, but nonetheless she felt terrible.
"I...I guess I didn't think of that." Fluttershy looked down, sniffling. "Rarity, I'm-"
"Stop." Rarity held her other hoof up to silence her. "Please don't apologize anymore, it won't make either of us feel any better."
"I should have been more honest with you in the first place, Rarity, the last thing I wanted was for you to feel bad," Fluttershy whispered. "I was just..."
"Afraid." Rarity gently nudged Fluttershy's chin upwards, making the pegasus look at her. "I know, Fluttershy, I know how hard confessing such feelings can be. But even if I didn't feel the same way, I would never reject you or stop speaking to you!" Only after she finished the sentence did she realize what she'd just said. Oh, drat! That wasn't how I'd wanted to tell her! Fluttershy blinked and looked up at her in disbelief.
"You..." A tiny, hopeful smile crossed her face. Rarity nodded.
"I love you, Fluttershy."
The pegasus blinked again and clapped a hoof over her mouth, as if not sure this was truly happening. Rarity covered that hoof with her own, lowering it to reveal Fluttershy's slowly growing smile.
"Rarity..." She sniffled. "Oh, Rarity. I...I'm so happy!" she cried, throwing her forelegs around the unicorn. Rarity returned the embrace, tears of joy filling her eyes as she buried her face in Fluttershy's mane. Oh, how soft and warm and incredible Fluttershy felt against her! Who needs the ultimate fantasy of True Love? Reality is so, so much better!
They pulled slightly apart after a moment, Rarity not letting go of Fluttershy but instead leaning her face closer, their noses almost inches apart. They were so close Rarity could almost taste her breath.
"Fluttershy..."
"Rarity..."
Their mouths met slowly, in a soft but meaningful kiss.
-x-
Watching from the background, Angel Bunny leapt into the air with a silent cheer as the two ponies finally realized and embraced their love for each other.
It's about time. I was sure getting tired of all her moping!
Not that he wasn't happy for her, of course. But a bunny sure could get tired of watching somepony mope when she could be feeding him.