AN. I wrote this for Vicki139 for her birthday. I'm not really a fan of the pairing, but it's what she wanted.
Rainbow Dash was bored. Very, very bored. Applejack was too busy with apple bucking season to hang out with, there was nary a cloud in the sky for her to clear, there were no strollers careening down that one hill for her to save and she just didn't feel like practicing to get into the Wonderbolts. The blue pegasus let out a huff of air, blowing her rainbow mane out of her eyes as she lay lethargically on a tree branch. She needed excitement. She needed danger. She needed adventure.
She needed Daring Doo.
Her mind made up she spread her wings, stretching them and pushing off from the tree. She had an egg head to go visit.
With her normal disregard for doors Rainbow flew in the library window. She could see Twilight Sparkle standing at her desk, scribbling away at something.
"Hey Twilight!" Rainbow called. The purple unicorn jumped, whirling around.
"Rainbow Dash!" she gasped.
"Hey." Rainbow grinned, "I came to read some Daring Doo.
Twilight sighed distractedly, "You know where they are. And next time? Use the door."
Rainbow rolled her eyes, "Yeah, yeah." She fluttered over to the book shelf that held the Daring Doo books. Selecting her favorite one she sat herself down on the stairs and began to read as Twilight went back to whatever egg head-y thing she had been writing.
Rainbow Dash glanced up from her book, gazing across the room at Twilight. The purple unicorn had her flank to the pegasus, her tail swishing happily and her horn glowing as she scribbled away with her quill. Rainbow licked her lips, enjoying the view. After a few seconds she shook her head, silently growling to herself.
Not thinking about Twilight like that. She's a friend.
Rainbow sighed. What was Twilight writing about anyways? She spread her wings and hovered across the floor, stopping just short of the unicorn's shoulder, peering at the paper on her desk. As Rainbow had expected, whatever Twilight was writing made absolutely no sense. Bored with the writing her magenta eyes slide unbidden to the writer. Twilight's horn was glowing with pale lavender magic as she directed the quill across the paper, casting shadows under her smooth mane. She was biting her lower lip slightly in concentration and her narrowed eyes were alight. Rainbow dash swallowed hard.
For an egg head, Twilight was awfully pretty.
The pegasus scowled and shook her head. Not thinking about Twilight like that! She repeated to herself, more insistently. Now, if only she could get herself to listen.
Twilight must have caught her movement out of the corner of her eyes –beautiful, shining, mauve, shut UP, brain, eyes- because she started, spinning to face the pegasus.
"Rainbow!" she gasped, "You scared me!"
Rainbow grinned sheepishly, "Sorry Twi," she cocked her head, "What're you writing?"
The mare grinned, apparently pleased that Rainbow was taking an interest in something outside of flying or adventure for once.
"It's about ionic bonding."
Rainbow blinked. Right. She knew exactly what that was. Understood it too. It was right up there with quantum physics, string theory and the inner workings of Pinkie Pie's mind. She nodded slowly.
"I… see."
"Yep!" Twilight continued happily, "See, when a positive ion and a negative ion are attracted to each other they form an ionic bond, which-"
Rainbow watched Twilight talk. The words weren't really sinking in, but she figured watching the way the unicorn's lips moved to form those words was far more interesting anyways.
"So positive and negative are attracted to each other?" the pegasus asked, quoting the one thing she'd actually picked up, an idea forming in her head. To Tartaurus with just friends.
Twilight nodded happily, "Basically. See-"
"You're pretty negative." Rainbow broke in.
Twilight blinked and scowled, "What's that supposed to mean?"
"Oh no!" Rainbow adopted a high pitched voice, "I forgot to send one teensy letter to the princess! She'll think I'm not taking my studies seriously! She'll make me take a test to prove I'm taking them seriously! I'll probably fail! She'll send me back to magic kindergarten! Not magic kindergarten!"
"Hey!" Twilight barked, "That was-"
"Oh no!" Rainbow smirked, "Fluttershy took the princess's bird! She'll probably banish her from Equestria! Or throw her in a dungeon! Or banish her and then throw her in a dungeon in the place that she banished her to!"
"Fine, fine!" Twilight rolled her eyes, "I'm negative! Happy?"
"Very." Rainbow grinned, "So does that make me positive?"
Twilight shrugged, magicking her quill to begin writing again, "I guess."
The pegasus's grin turned sly, "And positives and negatives attract…"
Twilight turned to look and Rainbow Dash, a slight frown gracing her face, "Yes, what are you-"
The purple unicorn was cut off when a mouth crashed against hers. She gasped, surprised, and Rainbow took that opportunity to slip her tongue in. The unicorn allowed her eyes to slide closed as she enjoyed the sensations of the pegasus's tongue running along her gums and playing against her teeth. Rainbow practically purred into the purple mare's mouth.
Unfortunately, the need for air soon made itself known, and the two ponies had to pull away, panting and blushing.
Twilight rested her forehead against Rainbow's, smiling softly.
"I think I like ionic bonding a lot more now."
Rainbow laughed.