The Inner Reveal

Ordinary High School Student Alice and her magical Bond Creature, Bob, have been secretly fighting off an Alien Invasion. Alice has gone through all the basics: She's hidden Bob in her bedroom, she's balanced going to school and saving the world, and she's managed to keep that annoying kid from the school newspaper off her tail. But things have become...complicated. Alice can no longer hide Bob from her family alone, and people are getting suspicious. So she spills.

Alice has just gone through The Inner Reveal.

A sub-trope of The Reveal, The Inner Reveal happens when, for whatever reason, specific characters decide to reveal details of which they and the audience have been fully aware to characters who were out of the loop. It doesn't have to be some world-shattering secret being revealed to the world, or, really, any world-shattering secret at all. It can simply be two characters who have been secretly dating finally making it clear to everyone else that they are a couple, or a male character finally making it clear to the Clingy Jealous Girl that he doesn't like her.

A very common trope in shows that involve a Secret Identity or The Masquerade in any way, shape or form. Note that if the information revealed isn't believed, then it isn't this trope. Situations like that should go under Cassandra Truth.

Examples of The Inner Reveal include:

Anime and Manga

Digimon Tamers: Takato eventually shows Guilmon to his entire class. What follows is an episode of middle schoolers playing with a little red dinosaur. Dawwwww. This case is unique in that there was no real reason for doing so until later, when Takato wanted to sneak Guilmon on the school camping trip.
In Magical Girl Lyrical Nanoha A's, the eponymous 9 year old heroine finally confesses to her parents that over the past half a year, she has been working part-time as a Child Soldier for Human Aliens on a job that could have very well left her crippled for life or dead. They take it surprisingly well (but then again, given her dad's background, they must have been very proud of her).
Shu explains about Voids (and the fact he's a member of Funeral Parlor) to a few of his classmates halfway through Guilty Crown.

Comic Books

Thanks to several retcons over the years, Peter Parker has had to do this on more than one occasion. Most notably, twice with the Fantastic Four.
In a special crossover, Superman calls out the fact that Captain Marvel had nearly killed the criminal he was attempting to subdue. The captain promptly turns into his schoolboy true self, Billy Batson, and explains that the criminal in question had hospitalized his best friend in an attempt to assassinate him. Superman is very much shocked that a kid has to deal with so much.

Film.

Happens off screen between the first and second Transformers films. In Transformers: Revenge of the Fallen, it's revealed that Sam's parents are fully aware of the fact that their son's car is a giant alien robot in disguise.
ET the Extraterrestrial: The kids obviously have to explain things to their mother when Elliot falls ill from E.T.'s Psychic Link. And this is moments before the government stepped in and placed their entire house on quarantine.

Literature

The Heir Chronicles: Jack and friends do have to explain their magical powers to their parents (and the local police chief) in the final book. The Roses had formed a truce and begun to launch a full-scale assault on their hometown, you see...
In The Dresden Files, Harry slowly starts revealing details of the magical world to his Badass Normal friend Karrin, when he needs her help.
In Deep Wizardry, the second book in the Young Wizards series, Nita and Kit repeatedly break curfew while trying to make sure that a Sealed Evil in a Can stays sealed, forcing them to come clean about being wizards to her parents. At first the adults think that it's a combination of trickery and hypnosis, so Nita and Kit up the ante by taking them on a trip to the Moon (Nita's younger sister Dairine is not happy about having been left out of the trip). Nita's parents (and eventually Kit's parents) seem to be unusually undisturbed about their children risking their lives to fight evil, but given that the only way to stop them would be to keep them permanently unconscious, that might just be the adults dealing with the hand they've been dealt.
The opening chapters of Jane Linskold's Thirteen Orphans were meant to be this for the main character Brenda, being brought into the full knowledge of lore that her father and others have inherited over the generations. What was planned as a gradual reveal turned into a crash course fairly quickly though.

Live Action TV

The plot of Alias begins when Sydney reveals her status as a spy to her fiance, and he is promptly killed by SD-6.
This happens gradually for Chuck with his close circle. The only two people still Locked Out of the Loop? Jeff and Lester.
In the season 2 finale of Buffy the Vampire Slayer, circumstances force Buffy to finally tell her mother about the supernatural world and the role she plays in it. She had actually tried once before, but her parents assumed she was crazy and put her in a mental institution for several months. This time, she's able to prove it.

Western Animation

A variant is offered in Static Shock. The titular hero's father quickly figures out that his son is Static when he's kidnapped in order to lure the locally famous superhero out.