Relatively Flimsy Excuse

Characters may often claim that others are their relatives when they have no relation to them, often to justify a character spending time around them without looking suspicious, or to mention why a character has suddenly appeared in their lives. They may also invent an entirely fictitious relative to get something done, often disguising themselves as said relative.

Such excuses are generally not very believable and tend to rely on the listener not knowing enough about the subject or the so-called relative to be able to discredit it, but few characters even consider seeing through them. Its also possible that someone might see through it, but really don't want to call them on it. (Are YOU going to tell the vampire his "brother" does not look anything like him?)

Compare Blatant Lies, which is more general. May often lead to Undead Tax Exemption in a situation where paperwork would be required.

Anime & Manga

 * In Magical Girl Lyrical Nanoha A's, after Hayate summons the Wolkenritter and wakes up in the hospital after fainting from shock, tells her doctor that they are her relatives. She later goes on to refer to them as her family.
 * In Death Note, Light introduces Matsuda (who is at that point going under an alias) as his cousin when investigating Aoyama and using some friends to prevent him from standing out.
 * In the Azumanga Daioh manga, Sakaki claims that a children's meal she is buying for the cat toy prize is for a relative.
 * In the Bount arc of Bleach, Renji is thought to be Ichigo's cousin while attending his high school.
 * In the Reigai arc, Nozomi claims to be Rukia's cousin-- Rukia's been living at Ichigo's place long enough that the Kurosaki family takes Nozomi in with no further questions.
 * In Mahou Sensei Negima, when Negi uses some magic pills to age himself into a teenager, he identifies himself as his own cousin. Naturally, this creates a whole new set of problems when one of his students falls in love with his "cousin".
 * Similarly, Kotaro is passed off as Natsumi's little brother to explain why he suddenly started living with her and her roommates.
 * In Higurashi no Naku Koro Ni, this is Rika's explanation for Hanyuu (as a cousin). Not too far off -.
 * Rito tells people Lala is a distant relative in To Love Ru. No one really pays any attention to this fact, seeing as she loudly declared that she was his bride, and it's not like she's subtle in her affections either, subverting the whole point of the lie. (As an excuse to why they are living together.)
 * In Superbook, a Bible character who met Chris and Joy when she was younger remarks about this, and they claim to be their own descendants, rather than explain that they have this book that sends them back to different points in Bible times.
 * In the Beach Episode of Mayo Chiki, the cast members who aren't in on Subaru's secret make an unexpected appearance and the main characters, in trying to deflect the question of why Subaru is in a bikini, introduce her as "Subaru's cousin Punyuru". Jirou immediately lampshades the ridiculousness of this explanation (or, at least, the name), but the others buy it anyway (well, most of them).

Comic Books

 * In current DC Comics "Conner Kent" is Clark's cousin who is being raised by Martha and Jonathan following his own parents' deaths, and "Linda Lang" is Lana's neice.
 * Superman might count as well - rather than the usual adoption route, current continuity has the Kents being snowed in for a few months after finding the rocketship, and claiming Martha was pregnant but hadn't told anyone.

Film
"Waternoose: Ah, James. Is this one yours?
 * Superman (1978). After the Kents find baby Kal-El in the wreckage of the Kryptonian starship, Ma Kent suggests that they tell people that he's the recently orphaned child of her cousin in North Dakota.
 * Terminator 2. John introduces the Terminator to Enrique as "Uncle Bob".
 * Monsters Inc., when Mr. Waternoose finds the disguised Boo:

Sullivan: Ah, actually, that's, uh... my cousin's... sister's... daughter, sir.

Mike: Yeah. It's uh, "Bring An Obscure Relative To Work Day".

Waternoose: Hmm. Must have missed the memo."

"Random Co-Worker: Hey, Sully, is the kid yours?
 * Also done rather humorously in a deleted scene:

Sullivan: No! She's, uh...

Mike: She's his...brother's niece!

Sullivan: *Beat* Which makes her my daughter."


 * In Back to The Future, Marty McFly introduces Doc Brown to his teenage mother as his "uncle."
 * In Wendy Wu Homecoming Warrior Wendy tells everyone at school that Shen is her cousin.
 * In Princess Protection Program Carter has to pretend that Rosie is her cousin.
 * In the film version of Chicago, Roxie tells a neighbor that Fred Casely is her brother.
 * In Kill Bill, the Bride tries to pass her ex-lover Bill off as her father when he unexpectedly shows up at her wedding.
 * In Aladdin, Aladdin saves Princess Jasmine from getting her hand cut off for accidental thievery by jumping in and claiming that his "sister" gets confused sometimes.

Literature
"Vimes: Nobby, how many grandmother's funerals have you been to? I mean, really?
 * In A Series of Unfortunate Events, the Baudelaire orphans' guardians relationship to them is very questionable. For example, the villain Count Olaf is a very distant relative, who gains custody because he is closest by location. It's possible, but not stated, that some of the characters who claimed to be weren't really related to the orphans.
 * In Terry Pratchett's Strata, it's a running gag that when people ask the protagonist for her autograph, they always claim it's for a relative, not for themselves.
 * Likewise in Soul Music: "It not for me, it for my boy Crag."
 * In Discworld, it seems like anybody who asks for time off work "to attend my grandmother's funeral" is actually covering for something else that they want to avoid inconvenient questions about. In Mort, when Death's apprentice Mort asks for a day off, Death forestalls the excuse by pointing out that he'd know if either of Mort's grandmothers had died recently. In one of the Watch books, the officers and men come to a formal agreement whereby the officers will accept the excuse without question so long as any given guardsmen restricts himself to a maximum of two grandmother's funerals per year.
 * Although there's a Crowning Moment of Funny that subverts this:

Nobby: Three, sir. Granny Nobbs wasn't quite dead the first time."


 * And later on, when a Troll officer is ordered to stop Sgt. Detritus he instantly asks to go to his grandmother's funeral. Colon questions it, and he responds, "It her or me, Sarge."
 * In Breaking Dawn, Edward tells Bella's father that Renesme is his niece that they're adopting. The kid is obviously their own, as she looks like Edward with Bella's eyes, but Charlie goes along with it because he doesn't want to know how they conceived and had a toddler within one month.
 * The Bible has Abraham lie about Sara, his wife, and claims that she's only his sister in Egypt and Gerar (which is in his case, only bending the truth, as she is also his father's daughter), because he fears he would get killed out of jealousy by the king. Isaac does the same in Gerar with his wife.
 * In The Last Unicorn, Schmendrick tells King Haggard that the Lady Amalthea is his niece. Haggard doesn't believe him, but he doesn't really care.
 * Ax is introduced as Jake's "cousin Phillip" when he tries to visit their school in Animorphs, though to be fair, his disguise does include DNA from Jake and his actual cousin. They don't seem to think about the fact that Jake's brother and their school's vice principal are both enslaved by the mind-controlling aliens the Animorphs are fighting and could tear this story apart if they were to encounter "Phillip" ... Though this could be justified in that Jake's brother doesn't seem to go to their school and the vice principal presumably doesn't have every student's family tree memorized.
 * In Les Misérables, Fauchelevent gets the convent to hire Jean Valjean as assistant gardener by claiming that they are brothers.
 * Inverted in The Dresden Files. Harry actually is related to, but that truth can't get out or there'll be dire consequences for pretty much everyone involved. So instead, when they have to meet up, they pretend to be gay.
 * Done in Harry Potter and The Deathly Hallows the seventh Harry Potter book, when Harry pretends to be Ron's cousin at Bill's wedding. Possibly subverted in that though Harry takes Polyjuice Potion, the kid he's mimicking is just a red-headed boy from the town the Weasleys live near, not an actual Weasley. It works pretty well though- so well that one of Ron's uncles wonders if Harry's his son.

Live Action Television

 * In The Sarah Connor Chronicles: They pretended Cameron was John's sister.
 * In the Red Dwarf episode "Better Than Life", when Arnold Rimmer meets Napoleon: "Could you just sign this for me. Make it out to my good pal Arnie from your dear chum Napoleon Bonaparte. It's not for me, it's for my sister Alison. ...we call her Arnie."
 * In the Star Trek the Next Generation episode "Rascals", Picard pretends Riker is his father (after having been turned into a child in a transporter accident), so the Ferengi who've captured the Enterprise won't think it's weird that they're spending time together.
 * Angel once claimed that Cordelia was "family" to get into the hospital after she had a psychotic breakdown. This was also played as him seeing her as family despite not being related.
 * In That 70s Show, the gay couple who move in next door to the Foreman's mention that in their last place they lived they had to claim to be brothers.

Theater

 * In Rent the lesbian couple claim to be sisters on occasion. Keep in mind that they are of different races.
 * And that it once happened immediately after they made out. ("We're close.")
 * Lesbians sometimes will say that someone is a "sister" to indicate that she is a lesbian. Less common now, it was much more common when it was dangerous to be out to the general public, women could say they were sisters, that someone was a sister, or inquire whether someone was a sister, or So-and-so's sister ("So-and-so" might be the name of the person suspected of being her girlfriend, or it might be a name that a particular community used; "Leslie" was a common one, and so were some of the names of popular musicians, like "Meg" and "Chris") as a coded way of indicating or inquiring about sexuality without accidentally outing the person, or herself, in doing so.

Web Comics

 * In Sluggy Freelance, Torg claims that Sasha is his sister to prevent Oasis from killing her out of jealousy.
 * In one PvP strip, Francis disguises himself as an old man who is returning a game for his (non-existent) grandson, and exchanges it for a copy of the same game. He then comes back as himself to return the unopened game for a full refund.
 * El Goonish Shive: Ellen is Elliot's magically created Opposite Sex Clone. She adopted the cover identity of being Elliot's twin sister, who had been in foster care most of her life.

Western Animation

 * On Danny Phantom, Dani claims to be Dani's second-cousin some-odd-times removed, when she is actually a younger Opposite Sex Clone. The two refer to each other as "cousins" afterward, apparently just for simplicity's sake.
 * Played with in one episode of Futurama, when Fry tries to deflect attention from what the Professor is saying by claiming that "Grandpa" is a bit senile. The Professor then angrily points out that he's not Fry's grandfather, Fry is actually his great-great-etc.-uncle from a thousand years in the past...which of course, just makes Fry's lie seem more accurate.
 * "You're his uncle, stupid! He takes after you! Oh, no...that means I take after you too! AAAAH!"
 * One episode of King of the Hill has the desperately-lonely Bill invent a visiting uncle just as an excuse to go with his friends to the airport.
 * On the American Dad two-parter where the family goes to Saudi Arabia, Haley is going to be arrested for being outside her home without a man when a random Saudi man comes forward and claims to be her brother. Possibly based on the Aladdin example above, especially since he winds up being her Boy Of The Week.
 * In Code Lyoko, after Aelita is retrieved from the virtual world, she had no known family or history that can be freely divulged without breaking The Masquerade. To deal with this, the crew passed her off as Odd's cousin. She also had a Fake-Out Make-Out with Odd in a later episode, but the issue was never addressed beyond that.
 * In Sym Bionic Titan, Lance and Alana pretend to be brother and sister and that Octus is their father.
 * Mr. Hyunh on Hey Arnold tries this in order to get a job promotion, tricking his boss into thinking Granpa Phil is his dad, Arnold is his son, Oskar's wife Suzie is his wife and the rest of the people living in the border house are related to him... of course, it doesn't work in the end - plus the fact that he's asian and noone else in his supposed family is.
 * The Ugly Americans episode "Attack of Mark's Clone" has this occur when