Twilight Sparkle chuckled nervously as she sat across the table from Fluttershy. “I’m really sorry,” she said. “I wouldn’t normally ask for anything like this. But you’re my friend and I wasn’t sure who else I could turn to.”
Fluttershy leaned in with eyes full of concern. “Anything, Twilight! I’m always happy to help a friend.”
“Well, you’ve got a lot of herbs and stuff, right?” Twilight fidgeted, looking down at her hooves.
“Oh my goodness! Are you sick?” Fluttershy frowned.
“No, no, nothing like that,” Twilight said, shaking her head. “It’s, um, more… recreational.”
With a gasp Fluttershy brought a hoof to her muzzle. “Twilight! I don’t have anything like… like that!”
“Well, not recreational, exactly,” Twilight chuckled. Finally she sighed and hung her head. She couldn’t keep talking around it like that, she knew. “Okay, so, Applejack and I… we’re having problems. I don’t… I can’t… well, I have a hard time… keeping up with her.”
Fluttershy smiled. “Well, that’s nothing to be ashamed of, Twilight. Applejack’s so strong, I bet she could outrun anypony except Rainbow Dash.”
“I, um, well…” Twilight stuttered. “I wasn’t talking about… running. I meant, well, in the… bedroom.”
“Oh!” Fluttershy blinked in surprise before her face returned the the same gentle smile. “Oh, Twilight. I know just what you need.”
“Really?!” Twilight beamed and wiggled her rump in excitement before she blushed and chuckled nervously, embarrassed by how eager she was.
“Oh yes. It’s very common for unicorns to have this problem when they partner with earth ponies.” Fluttershy got up and walked over to a nearby cabinet, opening a drawer and reaching inside as she sorted through a variety of bags and jars.
Twilight sighed. “Thanks, that’s a relief. I’m sorry for being so awkward.”
“This is nothing!” Fluttershy giggled. Soon she returned with a small cloth pouch and placed it on the table. “You should’ve seen my cousin ask me the same thing. We were both so mortified that we never talked about it again.”
“I can imagine!” Twilight laughed. Then she frowned and raised an eyebrow. “Wait, cousin? I thought you said this was a unicorn problem.”
“Oh, yes, I should have mentioned,” Fluttershy said. “My cousin Sunshimmer is a unicorn. There are a few in my family.”
Twilight blinked. “…Sunshimmer? I’ve got a cousin named Sunshimmer!”
Fluttershy brightened up. “Does she have a sun-shaped cutie mark with stars around it?”
“She does!” Twilight beamed and laughed. “Does this mean… we’re cousins?”
“I guess we are!” Fluttershy giggled. “I can’t believe it. What’re the odds?”
“Hmmm, well, given the population of-“
“Anyway!” Fluttershy interrupted cheerfully. “I can’t wait to talk about this more, but I know you must be excited to get back to Applejack and try this.” She leaned down and nosed the bag towards Twilight, the happy smile on her face shifting slightly to become a playful grin. “Take one just beforehand and you should last as long as she does. Let me know how it works.”
Twilight grinned back as she picked up the bag with her magic. “I’ll give you all the dirty details, cous-“
Both their faces fell and they stared at each other from across the table, blushing.
“Um,” Twilight looked away and chuckled. “I’ll, uh, I’ll just let you know if I need any more.”
Fluttershy nodded, letting her mane hang in front of her face. “Oh, yes. I have more. Come back anytime.”
“Will do!” Twilight said, lifting the bag with her magic and giving Fluttershy a strained grin as she backed out the door.
That was quite amusing. Poor Twilight would have issues keeping up with Applejack’s, ah, stamina, and so it makes sense she’d seek out assistance from Fluttershy. (Although it’s interesting she needs herbal assistance…but then I suppose it might be too difficult trying to whip up a spell to accomplish the same thing, or just not worth the effort.) The way they discover they’re cousins—which is a better way for them to be related than, say, being long lost siblings or something—is quite funny too. Twilight’s enthusiastic “I’ll tell you all the dirty details” before she becomes super embarrassed was probably the funniest part. A silly story, but a good one.