Being a twin is awesome. You get a best friend for life, someone who you know probably as well as you know yourself, and someone who'll you'll always feel close to even when miles apart. But, if you took all of your knowledge of twins from pop culture alone, you'd probably be grossed out or even terrified of them. Twins, especially of the identical variety, have built up a strange reputation in fiction for being perverted, freaky, manipulative, disturbed and even violent. From The Shining to Marvel's Ultimates universe, if you shared a womb in a fictional world, there is, unfortunately, a high chance that you'll grow up to become an absolute weirdo.
One of the strangest subtropes attached to fictional twin behavior is when the two twins in question enter into a romantic relationship. Though the phrase only permeated mainstream consciousness when it was used in Gillian Flynn's Gone Girl, it's been a mainstay in the fan fiction community for some time. Think of any made-up set of twins and there's probably at least one fan-written story online forcing them to hook up. It is also curiously popular in manga and anime, whether used as genre-aware fan service like in Ouran High School Host Club or as the foundation for the entire plot like in Yusuga no Sora. But, if you thought this taboo subgenre only popped up in tumblr blogs and Japanese pop culture you'd be wrong. Superheroes and super-powered twins in American and European comics, films and TV shows have been getting uncomfortably close as well for years, right under our noses.
15 LUKE AND LEIA SKYWALKER (STAR WARS)
You can't talk about twins-behaving-badly trope without thinking of the most famous space twins ever created. Though they were blissfully unaware of their real familial relationship at the time, that kiss that Leia plants on her twin brother in The Empire Strikes Back is always super icky to look back on. While the films were quick to drive a respectable wedge between them after this, there were plenty more sickening smooches in the tie-in comics.
Published by Marvel to fill time between Empire and Return of the Jedi, both Star Wars #23 and #25 showed the twins locking lips, with Leia nicknaming Luke "flyboy" in the latter. (Ugh.) In #61, Leia even admits to being jealous of a girlfriend of Luke's, and a few issues later following her death, a very charged moment between brother and sister is interrupted by someone whose timing they were probably extremely grateful for later on.
14 ANDREA AND ANDREAS VON STRUCKER (X-MEN)
Given that their powers rely on them touching each other, the von Strucker kids were probably doomed to a freaky fate from the start. The Aryan twins are the offspring of Baron Wolfgang von Strucker, proud owner of the most Nazi name Marvel could think of. He tinkered with their genes so that they were born with mutant powers of flight and plasma beam-shooting but only if they held hands.
Inevitably, through a combination of their Nazi upbringing (which always guarantees weirdness) and their physical co-dependancy, the Fenris Twins' relationship became overtly confusing enough for other characters to comment on it. To make matters worse, following Andrea's death, her brother -- in need of her contact to channel his powers -- had her skin tanned and wrapped around his sword hilt in New Thunderbolts #17, which sounds like a horrible innuendo.
13 OBSIDIAN AND JADE (INFINITY INC.)
Todd Rice and his twin sister Jennie-Lyn Hayden are the children of Alan Scott -- the original Green Lantern from the Golden Age -- and the supervillain Thorn. After a difficult childhood separated them from their parents, the siblings discovered and embraced their superhero heritage by forming Infinity Inc. in the spirit of the Justice Society.
As Obsidian and Jade, the twins remained close. Maybe too close. Though Todd would later come out as gay, before then, he lived a troubled life battling mental health issues and grappling with evil urges. Though they were certainly never intimate, his feelings about his sister were often confusingly presented in the comics, particularly when he admitted that she was one of the "only people" he'd ever really loved in 1996's JSA #110.
12 ALEKSANDR AND ALEKSANDRA ROMANOV (2000AD)
Russian twins Aleksandr and Aleksandra Romanov appear in Nikolai Dante, a 2000AD strip set in a futuristic world where the Russian revolution essentially never happened. In this Imperial Tsardom of swashbuckling rogues, rebels and space travel, the Romanov twins were born to a family hungry to dethrone the current autocrat, and with the biological weapons to pull it off.
Unfortunately, the pair were too often distracted making out with each other than fighting on the battlefield. When they did manage to break lip contact, they could activate their shared nanobot-powered ability to fuse into a huge, terrifying beast, which just made them even more intimately connected. Their urge for closeness on every level might not be surprising considering they were also the product of an illicit act between twins.
11 SCANTY AND KNEESOCKS
From the legendary studio Gainax, Panty and Stocking combines the visual style of The Powerpuff Girls with the mature and surreal humor of Adult Swim. If the underwear-themed names aren't enough of a giveaway, most of the show's laughs came from the crudest of places, with the series' early pair of villainous twins being no exception.
Scanty and Kneesocks served as the antagonistic demon sisters to Panty and Stocking's angelic heroics, and as main villains for the early portion of the series. They were designed to be the exact opposites of the titular sisters; rule-abiding, high class and possessing a love for one another that ran very deep. Though the icky undertones were there throughout the show, it wasn't until Episode 12 that our creeping suspicions were confirmed on screen.
10 ORION, NEKI AND CESTI ASSANTE (GRENDEL)
Matt Wagner's Grendel originally told the tale of a masked, devilish assassin who worked his way up New York's mafia hierarchy. As the story continued, Wagner skipped further and further ahead in time with others taking on the Grendel mantel, which became something of a poisoned chalice for all who dare wear the mask. Orion Assante was one such wearer in a distant, dystopian future.
Born of a noble and affluent family, he used the title to take over the world as "Grendel Kahn" with his twin sisters, Neki and Cesti, by his side as trusted advisors... and girlfriends. Weirdly, due to an AIDS epidemic, this type of twin relationship had previously become normalized for the purposes of safer intimacy. But, by the time the triplets started bumping uglies, it had largely fallen out of necessity, meaning the Assante kids' carnal desires were just as questionable as they would be now.
9 HANSEL AND GRETEL (BLACK LAGOON)
Black Lagoon is like a modern-day update of Pirates of the Caribbean but without the Disneyfication. Set in the early '90s in the Southeast Asian seas, "Lagoon Company" are a band of smugglers who have to compete with everyone from the Yakuza to the mafia to Colombian cartels for survival. Full of blazing guns and fast women, the manga and anime adaptations are squarely aimed at an older audience.
This is no more apparent than in characters like the deadly Romanian twins, Hansel and Gretel. Almost everything about these gun-toting orphans is ambiguous and confusing. They may or may not be murderous children and they may or may not be the genders they present as (they keep swapping clothes and wigs.) They also may or may not be in love with one another, possibly instigated by the shared trauma of sexual abuse in their earlier years.
8 JONAH AND JOHANNA CARLYLE (LAZARUS)
This ongoing series penned by Greg Rucka paints a possible future in which corporations have become so powerful that they've replaced governments and privatized the way the world is run. Heading up those ruling companies are Families who are served by a slave class called "Serfs." A "Lazarus" is someone who is "elevated" above their station and bio-augmented to become a Family's ultimate bodyguard.
Lazarus' central Family are the Carlyles, headed by patriarch Malcom. At the start of the series, two of his children -- twins Jonah and Johanna -- plotted his downfall together. Most of this plotting occurred in between them having sex with one another, just in case it wasn't quite clear enough how messed up this Family were. But, when one of their schemes goes wrong, Johanna doesn't hesitate to betray her brother/boyfriend.
7 PRINCESS NUALA AND PRINCE NUADA (HELLBOY II)
Though Princess Nuala served as a love interest for Abe Sapien in the Hellboy cinematic sequel, he had some stiff competition from an unlikely source -- her long-absent brother, Prince Nuada. The Elven siblings were the children of King Balor, the owner of the Golden Army, created to win the war against humans. Though only Nuala possessed psychic abilities, her time in the womb with her brother linked them permanently.
Their bond is empathic -- like the real-life link twins share but psychically heightened. Despite their differences of opinion on peace and war, this meant the two had a unique and unbreakable connection, uncomfortably blurring the line between familial and romantic love in their behavior around one another. Even the actors who played them have since agreed their performances had questionable subtext.
6 XIA YU FAN AND XIA YU LIN (FULL METAL PANIC!)
The Second Raid is confusingly the third anime adaptation of Full Metal Panic but technically the second season, as it picks up right where the first season ended. Similarly confusing in Second Raid is the relationship between the Xia sisters. Creator Shoji Gatoh has described the series as broadly being "Boy Meets Girl." More specifically, it's teenage paramilitary pilot meets fiery, high school student for contrived reasons.
The Xia twins are Chinese assassins who are given final orders by their adoptive father to take out the aforementioned high school student and love interest of the teen soldier in an act of vengeance. While the twins never transgress the line completely, in Second Raid they do obsessively hold hands and even shower together. Following Yu Lan's death, Yu Fan also has a vision of her sister appearing naked above her.
5 SMAX AND REXA (SMAX)
Smax was the spin-off series from Alan Moore's Top Ten. While Top Ten played with the superhero genre through the lens of a sci-fi police procedural, Smax took a hard left-turn into the fantasy genre. Titular hero Jeff Smax is called back to his homeworld for his uncle's funeral and brings his partner Toybox along for the ride, who soon realizes she's in for a lot more than she bargained for.
The reveal that Smax's world is populated by dwarves is a surprising one given than Smax himself is not a dwarf. In fact, he and his twin sister Rexa are the only non-dwarves in their family. The other shocker comes when we discover that his dwarven home is completely down with more intimate twin relationships, something Smax and Rexa have no problem participating in. In fact, they later use the guise of an unrelated couple back on his adoptive world.
4 ALEJANDRO AND MAYA HERRARA (HEROES)
Heroes began airing in 2006 just on the cusp of the big superhero boom in mainstream media. It lasted for four, award-winning seasons featuring a large cast of original superpowered characters trying to find their place in the world. In Season Two, we were introduced to Alejandro and Maya Herrara who were desperately trying to make it to New York in the hopes of managing Maya's deadly power.
Maya appeared to have the uncontrollable curse of willing people dead while her twin brother possessed the gift of being able to suppress it. Maya's reliance on her brother to stop from her killing forged a very intense bond between them, not helped by Alejandro tenderly assuring his sister she was "beautiful and charming." The fact that Maya became incensed by her brother's cheating wife to the point of killing her was also very telling.
3 SUPERBOY AND MISS MARTIAN (YOUNG JUSTICE)
No, these two (thankfully) aren't related in any way but that didn't stop the DC animated series from playing around with the too close twins trope in Season One. After a clear build-up of romantic tension between the Superman clone and shapeshifting Martian girl, it was only a matter of time before their relationship deepened. It's just a little unfortunate for them that the circumstances were so weird.
In "Terrors," the pair were tasked by Batman to go undercover at Belle Reve, posing as Tommy and Tuppence Terror, aka the villainous Terror Twins. While inside the maximum security prison, "Tuppence" attracts the affections of Icicle, Jr. and the ire of Killer Frost, who ends up trapping her in ice. Superboy rushes to free her, and, when she appears unharmed, pulls her into their first kiss... while they're still disguised as siblings. Cue Icicle, Jr. exclaiming, "Dude, that's your sister!"
2 JAIME AND CERSEI LANNISTER (GAME OF THRONES)
Aside from Luke and Leia, the Lannister siblings have to be the most infamous example of twinsidiousness in pop culture to date. In comparison, they also make the Skywalker twins' accidental smooch look downright normal. Though societal convention required them to hide their illicit affair for a long time, Jaime and Cersei see virtually nothing wrong with their relationship. In fact, Cersei views it as the most natural kind of love possible.
"Jaime and I are more than brother and sister," she clarifies in "You Win Or You Die." "We shared a womb, came into this world together. We belong together." Together, the Rich Kids Of Casterly Rock sired three kids and tried to pass off the Children of The Corn as Baratheons. It's also a rare example of twin coupling being an inciting incident, as the discovery of their taboo act kicks off a seismic chain of events.
1 SCARLET WITCH AND QUICKSILVER (ULTIMATES)
If anything else, this list proves that any supervillain who has twins REALLY needs to keep closer tabs on them. Pietro and Wanda Maximoff, the sometimes-but-sometimes-not kids of Magneto had no-one else but each other to fend off discrimination in their home country. Though they eventually became good guys, one thing that never changed was their inseparability.
Wanda's mental instability often causes Pietro to be very protective of her, underlying a sexual tension between the two that remained buried for years... until the Ultimates universe dug it up. There, their bond became more and more intimate, culminating in Wolverine catching them in the act and everyone strangely chastising Cap for being too square to be on board the twin-lovin' train in Ultimates 3.