I Can Never Resist A Challenge!
As Twilight walked away from the inebriated Princess Luna, she began to psych herself up.
"Well, she seemed fine to me," She noted simply. "Now, I'm gonna' take Rainbow down. There's no way she's beating me in a good, old-fashioned cider-chugging." She thought about what she was getting into as she walked back toward her friends. Rainbow was staring her down already, sizing up her opponent! She wasn't sure she was up to this. Sure, she drank regularly, and Dash didn't, but she'd had a few already.
"I could drink you under the table, any day!" Twilight protested.
Rainbow snorted, "Oh yeah?" She responded, "You're on! I bet I'd beat you in ten seconds flat!"
Already buzzed at that point, Twilight laughed and rolled her eyes. "You can kiss my sexy, purple flank if you think I'll lose!"
Rainbow narrowed her eyes challengingly. "Maybe I will kiss that flank of yours...if you win" She dared, smirking.
Twilight could feel heat returning to her cheeks at the memory. Shaking her head, she thought, "No! There's no way I'm losing to her! Not this time!" She quickened her pace and slid into the seat opposite Rainbow Dash. As she wordlessly signaled to the waitress for the first round, their friends stood back to give the mares room, but not so far back that they could no longer spectate. The mugs were swiftly placed in front of them, filled with amber liquid, frothing over the sides.
"It. Is. On!"
Within seconds, the first round was gone, then the second. "Jus' keep 'em coming!" Dash told the waitress. Slightly disturbed by the speed of their drinking, she nodded her head and ran off to get more cider. They finished the third round just the same, but slowed down after that. Neither of them wanted to get sick right off the bat. At some point, their friends all dispersed to celebrate the festivities in their own ways.
As they talked and drank the night away, they went largely uninterrupted, save for the waitress bringing them round after round and Princess Celestia coming to Twilight to hear how her sister was faring.
"...And then I said," Twilight had been telling Rainbow a story for the better half of an hour at this point, "But that didn't happen in the book!" The mares both laughed loudly at the joke. It rang through the ears of all attending. All around them, ponies were leaving. The band had stopped playing. Their friends and the princesses had all left already, as well. They had been having so much fun, they hadn't even realized that the party was leaving them, save for the bar. Though, it was mostly empty.
Rainbow giggled drunkenly as she looked at Twilight across the table with a half-lidded gaze. "Why don' we get ta jus'...talk anymore, Twi?" She asked. She had begun to slur her words around the seventh round. "I...I like you a lot. We need ta hang out more!" Her forelegs waved about wildly with her last sentence.
Twilight, on the other hoof, seemed more level-headed, though not by much. Her words had begun to slur, but she was still able to sit still without wobbling around. She giggled at her companion's enthusiasm. She already hung out with her more often than any of her other friends. "I'm sure we will, Dash," She looked around the dance and bar area and frowned at the inactivity. It was nearly dead. Beyond that, she was a mare who knew her limits. She turned back to Rainbow, who seemed to be staring at her dreamily. Twilight shrugged that off as the way the drink was making her act. "I think we should get outta' here, Dash." She said.
Rainbow raised a brow with a smirk. "So you admit I can drink more'n you cen?" She gibed. "Ready ta' pucker up, bookworm?"
Twilight blushed furiously. "N-no!" She countered, It's jus' that everyone else is leavin', and I'm afraid that yer gonna'-" She quickly wrapped Rainbow in her lavender corona, seconds before she would have hit the ground. "Think ya' cen walk?" She asked, concerned for her best friend. Defeated, Rainbow shook her head and was lifted out of her seat and onto Twilight's back.
"Aaawww," Rainbow mumbled sleepily, "You won..."
Twilight rolled her eyes. "Ya' sure do know how ta take a competition too far, don'tcha'?" She asked rhetorically.
"Got it down to a science..."
"There's no way yer flyin' home in this condition, so I'm takin' ya' ta my place. She paid the tab and promptly left the party grounds, Rainbow Dash draped across her back. Her lavender ear brushed gently across her cheek with every step. Rainbow Dash smiled at the soft, caressing feel of it.
Rainbow Dash had been gently snoring the entire way to the library so far, but Twilight could feel her move just slightly as she stirred awake. "Twilight?"
"Yes, Dash?" Twilight responded. She could see the library in the distance; they were almost there. She didn't look, but she heard the gentle bubbling of the fountain in Town Square to her left.
"I really do like you, like... a lot..." Rainbow seemed nervous to say that, but even when she wasn't drunk, Twilight could be denser than the Everfree Forest.
"Yes, ya' told me that already, Rainbow." She rolled her eyes and added jokingly, "Yer drunk."
Rainbow Dash shook her head as well as she could from her position on Twilight's back. "No, Twi. I mean it," She told the unicorn. She kissed her cheek lovingly, eliciting a deep blush from her carrier. "Thanks fer takin' care a' me, Twi."
After a moment of silence in which Twilight's head had traveled to a far off world where Rainbow Dash was this sweet way more often, she finally replied, "I-it's nothin' really." She smiled and turned her head so she could see the pegasus out of the corner of her eye. "I'll always be here to take care of you when you need it." She responded, suddenly sounding much more sober. That time, Rainbow Dash blushed, but she said nothing more as they approached the library.
Twilight gingerly opened the front door; it creaked in the deafening silence. Spike had long since been asleep, and without Twilight's supervision, had evidently passed out while reading in his favorite chair. She rolled her eyes and stepped further inside. The door made a soft click as it shut behind them. Twilight was careful not to bump into anything and wake the dragon as she traveled up the stairs and into the bedroom. Wordlessly, she picked Rainbow up with her magic and laid her gently on her own bed, covering her with a large, indigo comforter. She began to walk toward the guest bed when she heard a soft mewl of, "Nooooo," She turned to see Rainbow Dash looking back at her, pleadingly. "Please come sleep on here with me..." She begged.
Twilight sighed, but conceded. Rainbow Dash happily scooted out of the way for her, and she slid into place, facing away. Nervously, Rainbow tried to bring up the subject eating at her brain in the only way her drunken state would allow, "T-Twi..."
"Yes, Rainbow?"
"I...I meant what I said, that I like you...a lot."
"Dash, what are you talking abou-" She spun around to face the pegasus, only for their lips to meet, hers half open already. She moaned and sucked on Rainbow's bottom lip. She felt a gentle tongue lap at her lips, and she reached her own to meet it. They moaned into each other's mouths as they locked into a passionate kiss. Twilight raised her hoof to gently stroke Rainbow's mane while their tongues playfully wrestled with each other. After what both felt like an eternity and far too short a time, they broke the kiss, a small trail of saliva still adjoining their muzzles. Their cheeks were flushed with passion. Twilight went back in to give her one more, lingering kiss before she gently nuzzled into her neck and wrapped her in a tight embrace. "G'night, Rainbow..."
"N-night, Twilight."
Tired and drunk, sleep overcame the mares, and they were graced with pleasant dreams throughout the night, mostly of each other.
Rainbow Dash woke up first that morning. She tried to open her eyes, but she quickly squeezed them shut. The sunlight made her suddenly aware that her head felt like it was being torn in two by a jackhammer. With a groan, she attempted to pull the fluffy mass of cloud she felt in front of her over her head, yet when she grabbed it, it did not yield. In fact, it wasn't even cloud. It felt like...fur?
That was odd. She couldn't recall going home with somepony. Slowly, she eased an eye open, then both in surprise when her tired gaze was met with an equally tired amethyst one. "T-Twilight?" She managed.
"Mmm...Good morning, sleepy head. I thought you would never wake up." Twilight said. A gentle smile graced her lips, the ones that had felt Rainbow's against them just hours ago.
Suddenly, Rainbow Dash's head wasn't hurting so bad. Instead, it was swimming with thoughts. She frantically patted Twilight down, as if to make sure she was still there. "Wait, you're real? You're not a ghost pony, or somethin'?" She asked, incredulously.
"Why would I be a-"
She was cut off by an overzealous, "Woooohoooo!" As Dash jumped out of bed and did a flip in the air. Twilight's eyes went wide with surprise. "I just slept with Twilight Sparkle!" Dash exclaimed before ducking out the window and into the morning sky.
"Wait, but we didn't-" Twilight gave an exasperated sigh. It was too late...and she was far too hungover to deal with that! Catching and explaining things to an excited pegasus was future Twilight's problem...and future Rainbow Dash still owed future Twilight a big smooch on the flank.
Author's Note
Well...this was certainly fun! 
I hope you guys enjoy it as much as I did writing it. If you haven't read Surry's original story that this is merely a byproduct of, then I suggest you check it out. It's really fantastic! 
Please leave your comments, folks. I enjoy reading and responding to them. I get sad when I don't get them. 
Guys! There has been a reading done of this story already! Here's the link!
Thank you TheCaptainSand - Scarlett Blade AKA CaptainBron3y
