Two characters are caught in the middle of doing something they do not want others to know about, like talking openly about the Masquerade, fighting among each other or making out. Since the situation is blatantly obvious, the only option is to claim that it was all just an act. Probably for a School Play.
Bonus points if this gets taken so far that the play actually ends up being written.
- In Dramacon Derek says it at the beginning at a customer who caught Chris and him arguing.
- In the Power Rangers fanfic "Of Love and Bunnies", an argument between Rangers in a diner parking lot is excused as "a play they're practicing".
- The Infinite Loops: Sokka has found that no matter what implausible thing happens, he's been able to pass it off as simply the Ember Island Players rehearsing for a play. Even when this involves a blind, bright orange pony in a Stetson earthbending in broad daylight.
- The Monsters, Inc. example gets taken to extremes — there's another instance played straight in the movie ("She's Out of our Hair"), and during the credits the play does appear (the DVD includes the playbook, where basically everything was done by Mike Wazowski).
- In the opening scene of Incredibles 2, Tony Rydinger sees and recognizes Violet Parr in her superhero costume, as she's helping her family fight The Underminer. The next day, Violet tries to convince him that was all just her Shakespeare In The Park troupe doing a weird modern reinterpretation of Shakespeare.
- Ginger Snaps has a related example, when the girls, unable to clean up the place of a fatal accident quickly enough, mask it as the scenography for their morbid photographic art.
- The League of Gentlemen: The criminals use this excuse when some Camp Gay actors (including a young Oliver Reed) interrupt their planning session for The Caper. In this case the usual Blatant Lies is avoided, as the trope had clearly been prepared in advance.
- Men in Black. Agent K is interrogating Frank the Pug (an alien in the form of a dog) while holding him.
Agent K: Rosenberg mentioned Orion's belt. What did he mean?
Frank: Beats me.
Agent K: Beats you? [starts shaking Frank around]
[Frank starts yelping]
Agent J: [to a passerby] They're rehearsing a ventriloquist act.
- Moulin Rouge!: Gets taken so far that said play ends up actually being written.
- Used for comic relief in The Well of Moments. Jasmine and Wesley (an assassin) have an intense discussion over lunch about his missing brother: he thinks she killed him (she didn't), she denies creating the rumors he's still alive (she did). When their banter draws the alarm of another customer in the restaurant, they use this line. To sell the rehearsal excuse, Wesley drops his native Kiwi accent and asks if he's doing it right.
- The inversion also appears in Blackadder the Third, where it's set up by a Running Gag about how Prince George can't tell the difference between theater and real life.
- Buffy the Vampire Slayer: "Rehearsing a play" tends to be used if a Muggle catches the heroes talking about demons and monsters.
- In an episode of Cheers, Woody is in a play, but is afraid that his girlfriend Kelly won't approve. He hides it from her, but she eventually walks in on him practicing a kiss with his co-star. Kelly runs from the room crying. "You're in a play and you didn't even tell me!"
- Doctor Who: Invoked nearly word-for-word in "The Caretaker", when Clara is caught stopping an alien attack on the school where she teaches. Her co-worker/boyfriend is not impressed and immediately figures out that both the thing she's fighting and Clara's unfriendly co-conspirator are aliens, hilariously assuming that she is one as well. Ultimately it's played for drama that Clara would rather make up a completely obvious lie than try to explain what's really going on to her boyfriend, who would probably believe the truth.
- Friends: Ross says this when strangers overhear him arguing about how he got caught kissing Chandler's mother. Everyone seems to buy it at, at first anyway.
Chandler: Hey, you kissed my mom!
[People around the cafe look towards them]]
Ross: ...We're rehearsing a Greek play.
[Everyone buys it. Sometime later, Chandler grabs Ross's finger and bends it. Ross falls onto one knee, and everyone looks at them again.]
Ross: ...Still doing the play.
[Chandler twists Ross's finger. Ross groans in pain, before realizing people are looking again and covering it up with opera singing.]
- Inverted on I Love Lucy, too. One episode, Lucy suspected new residents in a neighboring apartment of being Soviet spies, and while snooping around in their apartment, she winds up hiding in the closet when they return and hears them discussing plans about executing an important espionage mission for a communist agenda. Lucy freaks out, calls the police, at the episode's conclusion, it turns out that Lucy's new neighbors are actors who were reciting their lines for a play. In a large part, this was a Take That! from Desi Arnaz, a Cuban, who, with wife Lucy, were both suspected of being communists in Real Life by... the FBI.
- The M*A*S*H episode "Hey, Doc" does the inversion with Radar and Klinger. One is proposing to the other.
- Played with on Neighbours: Ruth walks in on Amy and Lance in the midst of what appears to be a bitter breakup. They tell her they're rehearsing for a play. In actuality, they're rehearsing for a public breakup, staged so that Amy can get back in with her former best friend Jacinta, who she suspects of framing Lance and getting him suspended.
- At least once in Quantum Leap, Sam uses "I'm an actor practicing my lines" as an excuse when someone catches him talking to the Invisible to Normals Al.
- Inverted in an episode of Sanford and Son, in which Lamont is preparing for the title role in Shakespeare's Othello. Fred witnesses Lamont and his acting teacher Marlene rehearsing the scene where Othello strangles Desdemona, and mistakes it for an actual murder. Fred freaks out.
- In Soap, when Sally is making a scene in a diner because Burt told her that the two of them can't be together, this is Burt's excuse.
- Played with in The Wild Wild West episode "The Night of the Turncoat". A public disturbance involving the main characters is explained away by one of them as a scene from a play which their "troupe" has come to perform in the town. While technically untrue, in actual fact the whole thing was staged by the main characters as part of a larger infiltration plot.
- During a task in Grand Theft Auto IV, Niko has the job description described to him, in a roundabout, not really implicating way, in a car that his employer's other agent (the man explaining the job) thinks may have listening devices in it. Niko then bluntly sums up the assignment to be sure he understood, leading his co-worker to quickly state, for the benefit of anyone listening, that he does not really know Niko, and that they are rehearsing for a night school drama class they attend together.
- El Goonish Shive:
- A pizza delivery boy walks in on Male!Susan and Male!Nanase discussing skirts, and transformed Tedd tried to explain it away. The problem is, this guy's also the head of the student council in Tedd's school. Okay, not a big problem...
- Later, when Ellen and Nanase are caught kissing by Nanase's "Scary Homophobic Mother", Ellen claims "We're rehearsing a play about CPR!"
- The Simpsons:
- Inverted in one episode where Homer was heard shouting, "I'm going to kill you" in an angry tone, and Marge thought he had snapped. It turned out that Homer and Bart are rehearsing for a play, and Homer was just reading the play's title, I'm Going to Kill You, aloud.
- Which gets double inverted: seconds later, Homer appears to be reading from the play and says "Professor Van Doren — so good to see you." Then Professor Van Doren appears in the doorway and says "Ah, rehearsing a play, I see."
- Another Simpsons episode has Bart getting paranoid about a series of threatening letters from Sideshow Bob. One scene (part of a montage of similar Bait-and-Switch comments) has Mrs Krabappel telling Bart, "You're going to be my murder victim, Bart - in our school production of Lizzie Borden, starring Martin Prince as Lizzy."
- The trope is mentioned in the episode where Bart sees Principal Skinner and Mrs. Krabappel making out at a party. Skinner tries to convince Bart that he (Bart) just imagined it, prompting Bart to say "That's the best you can do? You could have at least said that you were giving her CPR or rehearsing a play!". Skinner then asks if it's too late to say that.
- In the Ready Jet Go! episode "My Fair Jet", Jet sings a song about how he is Bortronian. Then, Mr. Peterson comes over, and asks "Bortronian is what you what?!?" Sean and Sydney, desperate to keep Jet's alien identity a secret, claim that he was rehearsing for a play he wrote.