Didn't We Use This Joke Already?

Basically a situation or joke played earlier in the story reoccurs and a character breaks the fourth wall, to say "Didn't we use this joke already?"

Sister-trope to Oh, No, Not Again, in which a character comments in-universe on an action or event that is repeated in the story.

A Self-Referential Humor trope. Compare No Reprise, Please, Oh, No, Not Again, No Fourth Wall, Lampshade Hanging, Genre Savvy, Running Gag.

Examples of Didn't We Use This Joke Already? include:

Anime and Manga

In Furi Kuri during the second round of scenes done in manga style, one of the characters wonders why they are doing more manga scenes again.
There's a couple of instances of this on Sayonara, Zetsubou-sensei. For example, Nozomu brings up the topic of ignoring distressing things around you. Chiri says something to the effect of the show already doing this joke. Nozomu quips, "Ignoring that."

Literature

In The Fourth Bear, Inspector Jack Spratt is given a piece of evidence, a manila envelope with "Important" written on the front, and quips, "This could be important." When he shows it to Officer Mary Mary, she makes the same quip, but Jack informs her that he already made that joke, and she apologizes.

Live Action TV

In episode 2 of Monty Python's Flying Circus, an announcer says, "And now for something completely the same: a man with three buttocks," and gets a phone call pointing out that they did that already.
- Prior to that, the "Man With Three Buttocks" skit begins over again and stopped suddenly:

Interviewer: Didn't we just do this already?
Arthur Frampton: Yes.
Interviewer: Why didn't you say so?
Frampton: I thought it was the continental version.

Red Dwarf:

Cat: So, what is it?
Lister: Oh, someone punch him out!

A recent Wayne's World sketch on Saturday Night Live:

Winter's Bone! This joke has been done three times.

Radio

The short-lived sketch show Star Terk (sic) would have, Once an Episode, a gag where Captain Kirk would be asked an innocent-seeming question and answer "Uhura's bottom". In the last episode, Uhura deliberately provokes this at the start of the show. Later on, when Kirk is asked the usual question, he replies that they've already done that joke.

Video Games

In Batman: Arkham Asylum, the Joker tells Batman, "There were these two guys in a lunatic asylum... Oh hell, you've heard that one before, haven't you?" He is, of course, referring to the joke he told at the end of The Killing Joke, and that isn't the only reference to the story in the game.

Web Comics

Bob and George does this a lot with several of its jokes. The comic repeatedly lampshades it and even manages to go meta. The author admits in his notes he loves using this trope.

Dave Anez: So, in the end, it was a joke about reusing jokes about reusing jokes. Very postmodern.

Web Original

In episode 33 of Yu-Gi-Oh the Abridged Series, the "L'Oreal, because I'm worth it!" joke is reused, and Bakura says "I think we did that joke already."
In Super Mario Bros Z, an 'Over 9000' joke was made twice, and the perpetrating character was called out on it.
- The perpetrating character then tries to justify it by citing the 18-month gap between the two uses of the joke.
The Nostalgia Critic created many memes that he uses at certain situations, nowadays when one of these situations come up, he lampshades how everyone knows what's coming, and how predictable it is.

Stewie: I'm not going to no Jewish school! Sitting around all day with a bunch of short, hairy guys. I'll feel like I'm on the forest moon of Endor.
Chris: Didn't you make that joke the other day?

On The Simpsons, Mr. Burns plans to seal all of Springfield in a dome, until Lenny mentions that it's been done (specifically in The Movie).
- Also from The Simpsons, episode "Saddlesore Galactica":

Marge: Hmmm. Should the Simpsons get a horse?
Comic Book Guy: Excuse me, I believe this family already had a horse, and the expense forced Homer to work at the Kwik-E-Mart, with hilarious consequences.
Homer: [pause] Anybody care what this guy thinks?
Crowd: No!

Later in the same episode, Marge starts filling out a racing form. Lisa suggests that Marge might be developing a gambling problem, a nod to Marge getting hooked on slot machines in "$pringfield; or How I Learned to Stop Worrying and Love Legalized Gambling". Cue Comic Book Guy: "Hey! I'm watching you."

In an episode of Phineas and Ferb, they build a rollercoaster. Except this time, it's A MUSICAL! The trope title is practically quoted verbatim.
In the Tiny Toon Adventures parody of "Kon Tiki", this trope was utilized when the raft started to sink for a a second time.

Plucky Duck: It can't be! We did that gag already!
Sweetie Pie: What?! You're going to bring up redundancy now?!

South Park has used this at least twice:
- The episode "Canceled" begins identically to the first episode, "Cartman Gets An Anal Probe", until the boys start commenting that the experience is eerily familiar.
- "200" begins with some unenthusiastic namecalling between Cartman and Kyle, only for it to be pointed out that this routine has been done to death.
The Danger Mouse episode "Duckula Meets Frankenstoat" cracks a spoonerism, "a block of flats" for "a flock of bats," which gets repeated twice and duly noted by the cast.

Duckula: You will be surrounded by a swarming b-b-block of flats! He He He!
DM: We've done that one.
Penfold: Twice.
Duckula: (disappointed) Curses, foiled again.

In The Tick episode "The Tick versus Chairface Chippendale", the Tick, Arthur, and American Maid crash into the villain's lair, the Tick snarking, "Party's over, Chairface!" This seems witty, as it actually is the villain's birthday party, which he plans to celebrate with a Deface of the Moon. However, the Tick repeats the line a few scenes later, and American Maid does the same later still, causing Chairface himself to remark that the joke has gotten old by now. Of course, the Tick does it one more time, aiming the villain's own super-weapon at him as he does so, and the party is really over.