Pinkie barely suppressed her chuckles as she crouched down low amongst the twisted branches and waving leaves of a bush. Every time one of her giggles escaped the hoof covering her mouth, an quick and decisive “shush” was uttered in her direction from a bush right next to her own.
“Sorry Dashie,” Pinkie whispered, quickly clasping her hooves back over her mouth before she could start laughing. When she regained control, she once again lowered her hooves. “I think is one of the best pranks yet. Do we have a target yet?”
The bush next to Pinkie's shook. “Nah, the only pony close enough is Twilight, and I am not pranking Twilight.”
“Awww, don't wanna anger your marefriend?” Pinkie taunted in a hushed, sing-song voice.
Rainbow rolled her eyes. “You don't understand, Pinkie. Now that we are together, it's dangerous for me to prank her unless I want to start a full-on war. I think I may have rubbed off on her too much.”
Pinkie gave her most exaggerated pout, even if it was hidden by the leaves of her bush. “C'mon Dashie! What trouble can one little prank cause?”
“A lot.” Rainbow shuddered as she remembered the last prank she'd pulled on Twilight, and in turn the pranks that had been pulled on her.
“Dashieeeeeee,” Pinkie whined. “Please? I haven't pranked Twilight in so long...”
“I said no Pinkie, we'll just have to- Pinkie?” Rainbow paused, watching as Pinkie reached down and brought a small hose to her lips. “Pinkie don't you dare, she's gonna-”
Pinkie took in a deep breath and blew through the hose. The air rushed through it to its destination; a small whistle set between the roots of a nearby tree. The whistle, specially carved to make a specific kind of noise, sang its song – that of an injured bird.
Rainbow Dash bit her lip, looking out of the bush to see fi Twilight took the bait. To her horror, the unicorn stood from the bench she'd been reading on and tilted her head towards the tree. Breathing a sigh of relief when she didn't actually move, Rainbow shot a glare at Pinkie's bush. “She didn't take it. I'm telling you Pinkie, you have no idea-”
Without waiting for another warning Pinkie blew on the hose once again, long and low. This time Twilight took the bait and came marching over tot he tree with a concerned frown stretched across her muzzle. Rainbow's eyes widened in fear. “Pinkie no, please.”
“C'mon, Dashie,” Pinkie whispered as Twilight got into position beneath the tree. “Live a little.” Then she bit on a length of rope hidden behind the tree and pulled.
In a moment of slow-motion horror, stretched out for seemingly eternity, Rainbow watched as a bucket nestled safely within the branches of the tree came tumbling from its perched, dumping its contents onto the purple unicorn beneath it. A fine, red-tinted powder poured out, coating Twilight from head to hoof.
A beat of Rainbow's heart thrummed through her ears, and then the powder took affect.
“Rainbow Dash!” Twilight screeched as she fell onto her side, hooves desperately working across her skin and scratching at everything the itching powder had touched. Writhing about in the dirt beneath he tree, Twilight did her best to still her head for long enough to shoot a glare directly into Rainbow's hiding spot before losing focus and rubbing her neck desperately against the rough ground.
Eve as all the possibilities for Twilight's revenge raced through her mind, Rainbow couldn't help but snicker at her marefriend.
Suddenly,t he unicorn jumped up onto her hooves, trembling as her entire body continued to burn with an insatiable itch. Without thinking she made a mad dash for the only source of relief within range; the fountain in the middle of the park, currently surrounded by multiple groups of ponies. With a mighty splash Twilight dove into the shallow waters, rolling around in the fountain and struggling to wash the itching powder out of her coat and mane.
Rainbow Dash fell backwards out of her bush, laughing hysterically as Pinkie did the same. “See!” Pinkie prompted through her laughter. “Told you it was worth it!”
Unable to respond, Rainbow just kept laughing, knowing it wouldn't be long until she was on the receiving end of a prank. Staring up at the sun, Rainbow's laughter died in her throat as a silhouette leaned over her face and blocked out the sky.
“Hello, Rainbow Dash,” Twilight muttered darkly, mane and coat dripping and the remaining traces of itching powder making her rub at her forelegs. “I take it you've had fun today.”
Rainbow swallowed nervously. “It was Pinkie's idea?”
Twilight raised a single eyebrow. “Funny, I haven't seen Pinkie Pie anywhere.”
Face falling, Rainbow turned to the side and, sure enough, Pinkie had vanished. “No way... she's seriously gonna let me take the fall for this?” She muttered to herself, mentally noting to prank the party mare good for this little betrayal.
Leaning down, Twilight placed a single kiss on Rainbow's cheek before placing her muzzle right next to the pegasus's ear. “Be prepared, Rainbow Dash.” With those final, ominous words, Twilight lit her horn and teleported away with a flash.
Over the course of the following week, Rainbow found herself literal bathing in itching powder, tarred and feathered, covered in a green slime she didn't want to know the origin of, and every time she was somewhere very public. Not even her usual napping grounds were safe from her marefriend's vengeance, armed with a cloud walking enchantment and nearly limitless teleportation, Twilight was nearly inescapable.
Twilight would occasionally find herself on the receiving end of a prank – Rainbow's conscience would not let her humiliation go unpunished – but they were rare and nothing like the level Twilight's pranks were on.
Eventually, after finding her favourite napping cloud filled with cake batter rather than water and enchanted to rain upwards, Rainbow came stumbling through the front door of the library, exhausted and looking more like a batter-monster than a pony.
“That's it!” She cried, flopping to the floor and spattering batter everywhere. “I'm done. I give; you win.”
From somewhere within the library, a voice echoed. “Are you sure? You are the one who started this.”
“I'm done, Twi,” Rainbow insisted. “Besides, it was Pinkie, not me.”
“Oh I know,” Twilight's voice echoed. “And she'll get what she deserves soon enough. But you... I think one more good prank is in order. Accept it, and you'll be cleared of any transgressions.”
Rainbow sighed. “Can I at least shower first? This batter's starting to dry...”
Twilight's voice giggled wearily as a magical flash cleaned Rainbow's coat. “Ready?”
“Hit me.”
Hit her Twilight did. In an instant a thick, warm liquid flowed down over her head, rapidly coating her body and a small area of the floor beneath her. Rainbow squeezed her eyes shut, but a familiar scent made her open them even as the dark brown liquid continued to cover her.
“Wait... this is...” she stuck her tongue out, taking a small dollop of the stuff and tasting it.
“Chocolate?”
Twilight giggled again, finally walking to the front room of the library where Rainbow could see her. “Three.... two.... one... yep! Chocolate.” Her eyes narrowed. “Solidifies fast, doesn't it?”
Rainbow quirked and eyebrow, taking a step forward once the shower had stopped, only to realize the chocolate had indeed solidified, and had encased her hooves, along with the rest of her body. From head to hoof, she was now a life-size, chocolate pony.
Licking her lips eagerly, Twilight sauntered forward, circling her entrapped marefriend. “I felt like having some chocolate today. So... where should I start?”
“Uhh...” Rainbow's cheeks lit up a scarlet blush beneath their chocolate coating.
“Up here?” Twilight asked herself, nibbling some chocolate off the tip of Rainbow's ear. “Or maybe... somewhere else...?