Don't Tell Mama

"Sheriff: All right now, boys, that's enough. Kid Rock, that's not like you. And Joe C., would your mama want you stretching out that sweatshirt like that? Joe C.: No, sir. Please don't tell Mama."

- The Simpsons

"Jade: Doesn't she know Valmont is a thief? Tohru: No, and please don't tell her."

- Jackie Chan Adventures

Everyone knows that Even Bad Men Love Their Mamas. And since that's the case, a lot of bad men, whether they might be gangsters, Career Killers, Corrupt Corporate Executives, Hitmen With A Heart, Gentleman Thieves or Anti Heroes in a morally questionable job will try to do their utmost to keep their mothers from knowing what it is they really do. This can even extend to getting enemies to join in on The Masquerade in order to keep her blissfully unaware.

Naturally there are many variations on this, as the character in question may be trying to keep the truth from a father, sibling, True Companions, etc.

Some criminals doing this often like to think of themselves as The Dutiful Son, providing for and protecting their mother or family while also keeping the knowledge of where the family's prosperity comes from secret, but their true status will depend on their other actions, as the character in question may be anything from a Complete Monster to a Delinquent to an Anti-Villain. In many cases this trope is merely a source of Wangst or Pet the Dog moments, but when the secret is sufficiently important, it can turn into Poor Communication Kills.

Of course, plenty of the mothers know what their sons do, they just either are in denial about it or not saying anything about it for the sake of family peace and quiet.

Often requires at least some Parental Obliviousness in order to work. Most characters that engage in this do so because they desperately crave hearing those magic words "I'm so proud of you" and don't want to make it go away.

Anime and Manga

 * There's a variation in Code Geass, where Lelouch tries to keep his alter ego secret from his sister.
 * Anti-Villain variation in Magical Girl Lyrical Nanoha, where the Wolkenritter keep their gathering Linker Cores to complete the Book of Darkness and save Hayate's life a secret from Hayate, knowing that she would not approve. She eventually finds out about what they were doing during the final battle; the Wolkenritter apologize, and Hayate forgives them.
 * Death Note has Light Yagami, the protagonist of the series, who tries not to let his parents and sister know that he is Kira.
 * Though that's probably more for practical reasons than emotional ones. His father is the chief of police, after all.

Comics
"Becky: Sure, you could have protected my mom! Sure! You could have moved her into Old Town and let her know her daughter's a god damn whore!"
 * Lieutenant David Elliot Hanneth Solomon, from Soda, is a cop faking to be a priest for the sake of his beloved cardiac mother.
 * In the original Sin City comic, Marv visits his mother's apartment to pick up the handgun he stored under his childhood bed. When his noise wakes her up he tells her some lies to reassure her about himself and why he's there that night.
 * Also, Becky from The Big Fat Kill gives this as part of her reason for.


 * In the original The Hood mini Parker Robbins keeps lying to his mother about him being a Super Villain. Helps that she has Alzheimer's and doesn't remember when he changes his story.
 * Sandman, a Fantastic Four and Spider-Man villain, completely kept his mother in the dark about being a villain. He even explained that he changed his name when he became a criminal so she wouldn't find out.
 * During Norman Osbourne/The Green Goblin's original death in Spider-Man his last words were a plea to Spiderman not to tell his son Harry Osbourne that he'd been the goblin. This carried over to the first Spiderman film.
 * For that matter, Peter Parker has gone to great lengths to hide his Superhero identity from his Aunt May, who is as good as his mother. In at least one version May has arachnophobia and is thus not overly fond of Spiderman, hence Peter's actions.
 * And when she died the first time she revealed that she'd known for quite some time, and was very proud of him.

Fanworks
"Near: Are we sure we want to do this? Mello: It's not like you to have doubts. Near: I don't usually face such definite trouble. Matt: That is the one thing we can guarantee will happen. We still in agreement over who to confess to? Mello: Light? Near: Light."
 * In Constant Temptation Mello, Matt, and Near find themselves in a position where they have to confess to spying on L and Light. They don't want L to know about it, even if it means facing Kira's wrath:

Film
"Carter: Luke, I know what it is you do, and the only reason why I ain't busted your ass is because you're my cousin... and it'd kill Aunt Bootsie. Luke: ...Why you gotta put Aunt Bootsie in this?"
 * Heavy subversion in American Gangster. Frank Lucas spends the whole film treating his mother like an unwitting Innocent Bystander, but towards the end of the movie she tells him that she never asked him where all the family's prosperity came from just so that she wouldn't have to listen to him lie to her. Furthermore, she goes on a near Hannibal Lecture about he's responsible for all the other members of his family being in the drug trade, because they never would have gotten into it if not for him. However she says that all of them, including her, will walk out on him if he does something as suicidally dumb as declare war on the cops, which was exactly what Frank was planning to do at the moment.
 * In Rush Hour, Detective Carter gets certain information from his criminal cousin by threatening to arrest him, thus notifying their Aunt Bootsie about his dealings.


 * There was one part in the movie Bulletproof where Damon Wayans' character goes along in lying to the mother of Adam Sandler's character in order to reassure her. Note that he blames Sandler's character for shooting him in the head, which shows both how far this trope and Rule of Funny can stretch.
 * This is parodied in Johnny Dangerously. It's painfully obvious to everybody (including the pope) except for Johnny's mother and his brother that he's a mob boss.
 * In Scream when Sidney informs that she's called the police about the murders, he pathetically breaks down and cries "My mom and dad are gonna be so mad at me!"
 * IIRC, Joe Pesci's character from Goodfellas lied to his mother about why he and the guys were there that night to keep her from finding out that he'd just killed someone for no real reason.
 * Inverted at the end of the first Spider-Man film. "Peter... don't tell Harry." It takes an actor of Willem Defoe's caliber to do all the things the Green Goblin did in that film and still make that last request a Tear Jerker - and it's doubly poignant when you realize that Peter honored that request. Led to Poor Communication Kills in the following two movies.

Literature

 * In Harry Potter, when Hermione finds the Weasley Twins testing out their home-made joke candies on younger students, Hermione demands that they stop. They taunt her by saying "Or what? You'll put us in detention?" Hermione coldly responds with "No. I'll write your mother." This scares the Twins so badly that they immediately comply, an action that has never been seen before or since.
 * And for very good reasons.
 * Odd inversion: Peter Wiggin of Ender's Game and the  Ender's Shadow sequels, rather than having to hide an evil secret, is reluctant to let his parents find out that he has a secret identity as the great Chessmaster named Locke. When he tells his parents, it turns out that they already knew; and as it happens, Bean and Sister Carlotta knew that Peter's parents knew before Peter knew it.
 * In The Thorn Birds (though not the better-known film adaptation), protagonist Meggie's oldest brother Frank runs away from home when she's a girl, after having a fight with their father. Years later, their mother, who doted on Frank, happens to find a newspaper in which an article announces his conviction for a terrible crime. Frank's only comment to the press was "Don't tell my mother."
 * Artemis Fowl really doesn't want his mother to know he's turned to a life of crime in order to sustain his family and continue the search for his Disappeared Dad, even if she does suspect he takes after his father in this aspect.
 * In Guards Guards, one of the things Constable Carrot does on his first night on patrol is shame a bunch of bar-brawling dwarfs into behaving themselves by asking what their mothers would say if they found out.

Live-Action TV
"Omar Little: I damn near got that woman killed, yo. Y'all should've seen me in Sinai Hospital while they stitching her up, lying about why somebody wanna shoot me down the street. That woman think I work in a cafeteria. Kimmy: Cafeteria? Omar Little: At the airport, yeah. Kimmy: The airport? Why the airport? Omar Little: 'Cause I know she ain't gonna never go down there to go dining, that's why! Hey, yo, Kimmy, this ain't funny, yo! That woman raised me!"
 * On The Wire Omar Little becomes enraged at rival gangsters after they violate the Sunday truce and blow his cover to his elderly grandmother.


 * Spy turned The A-Team style gun for hire Michael Westen from Burn Notice spent a long time trying to keep his mother in the dark about things, but ultimately had to break the news to her. Since then, she has played small roles in his operations, even once getting information out of a captive after Michael's interrogation techniques didn't work. Despite this, she wishes he would settle down, and the things she is asked to do sometimes unsettle her.
 * A running gag on Hill Street Blues was Belker constantly booking the same criminal for various minor offenses and the criminal always giving him a fake name. This went on for years, until the criminal was accidentally caught in the crossfire of a gunfight he had nothing to do with. He was mortally wounded and asked Belker to call his mother, finally giving Belker his real name. Belker did so, telling the criminal's mother that her son had been a fine, upstanding citizen.
 * In one episode of Brimstone, Zeke finds out that Gilbert Jax, the guy who raped his wife, is one of the 113 souls that escaped from Hell and that he has to find and send back. He also finds out that Jax has started with his old pattern again. He finds out that Jax is living with mother again, and tracks him to the mother's house. There he encounters the mother and talks to her, although he doesn't have the heart to tell her the truth about her son. Jax returns home at that point, and screams that "Getting my mother involved in this is low, Stone". Zeke defeats Jax, but afterwards still doesn't have the heart to tell his mother the truth, and lets her believe that he sent her son back to Heaven instead of Hell.
 * Inverted on Wiseguy, where federal deep-cover agent Vincent Terranova is forced to mislead his mother into believing he's a criminal. He's deeply troubled by how disappointed she is in her "no-good" son, and immensely relieved when she eventually learns the truth.
 * On Malcolm in the Middle, Hal and Lois leave the boys home alone for the weekend, and a drug gang commandeers the boys' house for their own purposes. The boys try to think of ideas to get the gang to leave, and Dewey (the youngest brother) suggests telling their mothers. This sounds like a childish idea when Reese and Malcolm first hear it, but it turns out to work perfectly: the gang members' mothers show up, and the whole incident induces enough shame in the gang members that they abandon their plans to take over the main characters' house.
 * One The Man from U.N.C.L.E. episode had two brothers, feuding THRUSH middle managers, concealing both the feud and the nature of their employment from Mama ... until she turned out to be the THRUSH supervisor who showed up to inspect their operation.

Theater

 * Cabaret is the Trope Namer: the so-titled number features Sally Bowles, decked out in a Naughty Nun outfit, singing about how her mother thinks that she's a real nun at a convent in France while she's really living up the seedy life. The trope itself is not actually invoked in the story however, merely in the performance of the song.

Video Games
"Shane...please...don't tell my mom..."
 * Subversion: Tony's mom in Grand Theft Auto Liberty City Stories. She knows and approves of his job, and even puts a contract on him when she's dissatisfied with his advancement.
 * SWAT 4. The serial killer in the second mission sometimes reacts to being handcuffed with this phrase.
 * Ofcourse the chances are that you already tazed or mazed her at this point.
 * Invoked in Simcopter; one of the phrases the player can shout at criminals to distract them is, "Does your mother know what you're doing?"
 * Dead Rising: "".
 * Haze: After you fatally wound, he apparently realizes, for the first time, all the atrocities he's committed while being high on nectar. His final words?

Western Animation

 * Drakken's mom was probably the single funniest thing in Kim Possible, one of the reasons for this being that she completely believes he is a radio talk show host. This despite the fact that he studied robotics, not psychiatry. Then again, anyone would want to cover up the fact that their world domination schemes were foiled by teenagers.
 * Tohru's mom in Jackie Chan Adventures is unaware that her son is working as a thug for Valmont and not knowing that the latter is a Diabolical Mastermind.
 * Well she knew OF Valmont but just thought he was a rich gentleman. It would seem like a HUGE step down to go from bodyguard to a multi-millionare to storekeep.
 * The Simpsons provides the page quote. When they went to Florida during Spring Break, the local sheriff was disappointed with Joe C. (the foul mouthed little person who toured with Kid Rock). A parody as much as anything, given the utterly inconsequential matter.

Real Life
"Don't tell mama I'm a pilot; she thinks I play piano in a whorehouse."
 * There's a Stock Joke in aviation that goes:


 * Variations on the same joke refer to lawyers, politicians, and other Acceptable Professional Targets.