Pinkie Pie: Sure, Rainbow Dash and Fluttershy had to house-sit for that vacationing bear, but what are the chances all my other friends would have plans this afternoon, too?
Written by Meghan McCarthy
Pinkie Pie holds a birthday party for her pet alligator, Gummy, inviting all her friends. Afterwards, all the guests compliment Pinkie on the great party, with Twilight saying "We should do this again soon!". Pinkie, being Pinkie, interprets this a little too literally...The very next day, Pinkie shows up at each of her friends' houses, eagerly offering invitations to Gummy's "after-birthday party" that afternoon. Her friends, however, aren't as enthusiastic...
Twilight/Applejack/Rarity:This afternoon? As in, "this afternoon" this afternoon?
(Fluttershy and Rainbow Dash don't get a chance to say this, as Pinkie Pie finishes their statement for them.)All of them offer excuses for why they can't come, but it isn't until Pinkie gives herself time to think about it that she realizes this.Once she notices Twilight picking up a package from Sugarcube Corner (instead of studying, like she said she would be), Pinkie decides to investigate. After sneaking around Ponyville in disguise, overhearing several secret conversations between her friends, angrily chasing Rainbow Dash around town, and a tense exchange with Applejack, Pinkie suspects that her friends don't like her or her parties anymore. To get some confirmation on her suspicions, she interrogates Spike into giving her information, even bribing him with a bowl of gems, but gets frustrated when he doesn't know what she's talking about.
Pinkie is satisfied at seemingly having her suspicions confirmed, but immediately feels depressed and lonely upon thinking she's lost her friends, to the point where her poofy hair deflates and her color scheme becomes muted and dull.In her mentally unhinged state, Pinkie ends up holding a morose and disturbing second party with several inanimate objects as her new "friends". Rainbow Dash stops by, apologizing for her behavior earlier, and offers to take Pinkie to Sweet Apple Acres. Pinkie repeatedly refuses to go, leaving Rainbow Dash no choice but to forcefully drag her there. Upon arriving at the farm, Rainbow leads Pinkie to the barn, where a surprise party is being held with all their friends. Pinkie assumes this is a surprise farewell party to celebrate her being booted from the group, until everyone explains that it's her own surprise birthday party. Pinkie, realizing she'd forgotten it was her own birthday, returns to her old cheery self and decides to enjoy the party. Twilight writes to Princess Celestia from the party, stating the Aesop that one shouldn't expect the worst from their friends.
Tropes present in this episode (YMMV tropes can be found here):
How her friends get out of going to Pinkie's after-party, and then how they cover up their own goings-on.
Rainbow Dash draws a wristwatch on her hoof, right in front of Pinkie, and then points out "Look at the time!" to try to get her and Fluttershy away from Pinkie.
At one point Applejack says that Pinkie can't come into her barn because they're renovating it and there's too much construction going on. The other ponies back her up by making blatantly fake tool noises.
Censored for Comedy: When the episode airs on Treehouse TV in Canada, all instances of the word "loser" are silenced.
"Rocky:" Not so bad? Puh-leeze! They're a bunch of "losers"! Pinkie Pie: Oh, come on now. "Loser" might be a little strong, don't you think? "Sir Lintsalot:" After the way they treated you, I'd say "loser" isn't strong enough!
Comedic Sociopathy: Spike is oblivious to Pinkie's angst during and after the interrogation, even though it should be perfectly obvious to any observer, and this ends up making things worse. Granted, he's got a pretty bad record of reading people from before too (not noticing that the audience hated Pinkie Pie's performance in "Over a Barrel" and Rarity's fashion show in "Suited for Success", thinking his crush on Rarity is a secret in "Green Is not Your Color", almost all of "Owl's Well That Ends Well"...), but this is the most extreme example, with him only being interested in the "nice spread" - a huge bowl of gems - and saying whatever it takes to get his claws on it.
After hearing her friends' increasingly Blatant Lies about why they can't come to the after-party, Pinkie somehow finds Rainbow Dash and Fluttershy's absurdly convoluted Stereo Fibbing the only one that seems plausible.
Spike has no clue about what he's being interrogated for or about, nor does he get one at any point. Ironically, this means he ends up frustrating Pinkie Pie with the same kind of literal-minded, cluelessly irrelevant answers you'd expect from her in a similar situation.
Companion Cube: Pinkie's 'new friends'. A pile of rocks, a dust bunny, a bag of flour, and a pail of turnips.
Death Glare: Pinkie gives one to Applejack. It's scary enough to rival Fluttershy's.
Discreet Drink Disposal: After the Spit Take, Rarity politely continues drinking, but once Pinkie's back is turned she discreetly spits her mouthful of punch into a potted plant.
Double Take: Rainbow Dash first casually says "Hi, Pinkie Pie" to a disguised Pinkie, before freezing on the spot with her mane and tail hair completely straight.
Dramatic Spotlight: Parodied. Pinkie Pie draws the (wrong) conclusion that her friends have all turned against her from her interrogation of Spike, and declares so in a Dramatic Spotlight. Then it turns out the light comes from the lamp she used to interrogate him with, as he turns it off.
Et Tu, Amici?: Played for Laughs when Pinkie Pie thinks that her friends don't like her parties anymore, only to realize that her friends are setting up a birthday party for her.
Exact Words: Spike tells Pinkie exactly what she told him to say in order to get the bowl of gems she was bribing him with.
Fauxshadow: Most of what happens at Gummy's birthday party... except for Pinkie saying "I can't tell you that, silly; then it wouldn't be a surprise!"
Felony Misdemeanor: Spike "confesses" (with much dismay and shame) to spilling juice on one of Twilight's books, using up all the hot water, and doing muscle-man poses in front of a mirror when no one is watching.
Forgotten Birthday: Inverted. It's only at the end that Pinkie realizes it's her own birthday, and the others had made plans to throw her a surprise party well in advance.
Furry Reminder: See the first example under Ass Kicks You above. Twilight and Fluttershy just shrug off getting butt-slammed into walls and return to enjoying the party. Horses are known for getting rambunctious in their play; this is why roughhousing is sometimes called "horse play".
Got Me Doing It: Rainbow Dash briefly talks back to "Rocky" as if she's actually mad at "him", before she realizes what she is doing.
"Rocky": You heard th' lady! She ain't goin' nowhere, chump!
Rainbow Dash: Who're you callin' a chump, chump?! [beat] Ugh... That's it: party's over.
Hidden Depths: You wouldn't have believed that an episode of My Little Pony starring the silly party-crazy member could be so profound… and creepy.
Innocently Insensitive: Spike is more concerned with the plate of jewels than how Pinkie's feeling. He's just managed to convince her that she's lost all her friends and no-one likes her parties. She appears ready to burst into tears; Spike's happily munching minerals.
Interrogated for Nothing: Spike honestly has no idea what Pinkie wants to know during his interrogation, so simply tells her what she wants to hear. Ironically, he might have known or guessed about the surprise party, so if she'd merely asked him what her friends were doing that afternoon, he might have been able to tell her, and avoid all of the unpleasantness.
Ironic Echo: There are two occasions when Pinkie Pie is staring at Applejack and then stops after saying "Okey-dokey-lokey." The first time she says it happily and it signals a relief of the tension. The second, not so much.
Letting the Air out of the Band: Twilight rings the counter bell at Sugercube Corner while happy, carefree music plays. Then Twilight reminds both the music and Mrs. Cake that this pick-up is serious business.
Pinkie: Oh, Twilight, you shouldn't hit the books. You should really just read them.
Twilight: I'll keep that in mind!
Locked Out of the Loop: Pinkie doesn't realize that the reason her friends are avoiding her is because they're planning her own birthday party until the very end.
Minimalist Cast: Only the Mane 6, Gummy, Spike and Mrs. Cake show up in this episode, with the last two only in one scene each. The first shot is the only time that background ponies appear.
Nice Hat: In-universe, anyway; Pinkie's invitation basket hat.
Rarity: Love the new hat. Very modern. What's the occasion?
Nice Job Breaking It, Hero: If Spike had told Pinkie Pie pretty much anything else, then we probably wouldn't have seen Pinkie Pie suffer Sanity Slippage. To be fair though, he had no idea what she was going on about and her prodding didn't help things.
One-Person Birthday Party: Pinkie celebrates a party with a bunch of inanimate objects because her friends were busy, and she thinks that they don't want to be her friends anymore. However, she had forgotten that day was her birthday, only remembering upon Rainbow Dash forcing her to go to her surprise party.
The eponymous "party of one" isn't like Pinkie's usual parties. Instead a childlike birthday party, it's more like a adult formal dinner party. She also drops her quirky vocabulary and starts to use a more serious tone and more formal words. Finally, her attitude towards her "new friends" is somewhat distant.
Paper-Thin Disguise: Inverted. Pinkie's sneaking disguise is anything but paper-thin, using wacky glasses, a hay bale, a trenchcoat, and a beanie, but Rainbow Dash is still able to recognize her instantly, without even reacting as if it's odd. Pinkie's probably the only one who would ever use that disguise. And Pinkie's behavior is so random most of the time, her friends have pretty much come to expect this of her.
Perp Sweating: Pinkie Pie does this to Spike in an attempt to find out why her friends are avoiding her.
Saying Sound Effects Out Loud: When Applejack claims that there's lots of construction going on in the barn, Rainbow Dash stage-whispers, "You heard her! Construction!" Cue a lot of ponies attempting to vocalize the sounds of power tools, including Rainbow Dash saying "Drill, drill!" as well as Twilight saying "Safety gear!"
Screw This, I'm Outta Here!: During his after-birthday party, Gummy turns away when he sees Pinkie Pie's inanimate guests. In the next shot of the whole table, he's gone.
Spit Take: Rarity does one right at Pinkie Pie's face when seeing Gummy in the punch bowl; she doesn't seem to notice and/or care.
Stepford Smiler: When Pinkie Pie's smiles are fake, you know something is very, very wrong.
Stealth Pun: Gummy sneezes for no apparent reason after popping out of the top of the bale of hay Pinkie is wearing. Presumably, it's a case of hayfever.
Stereo Fibbing: Even Rainbow Dash's and Fluttershy's body language reflects their Stereo Fibbing. Whoever says "Playing beach volleyball!" waves her front hooves above her head, while whoever says "Collecting seashells!" waggles them up and down at chest level. When their stories mutate into "Collecting volleyballs!" and "Playing seashells!", each pony waves one hoof above her head and waggles the other up and down by her side.
Super Speed: Pinkie Pie shows once again she can keep up with Rainbow Dash without trouble, leaving a pink streak behind her.