Anybody vaguely familiar with Anne McCaffrey’s beloved Pern series knows her books are packed with psychic dragon sex. But Pern isn’t the only alien planet with sexy dragons. Why is there so much dragon-related sexuality in science fiction and fantasy?

Though there are probably precedents for the dragon sex fetish in the pages of kinky horror pulp Weird Tales, I think it’s safe to say the phenomenon was popularized by McCaffrey and her Pern novels. These books, published starting in the late 1960s and continuing into the present, focus on a civilization of humans who evolved from the crew of a spaceship of colonists who landed on planet Pern. Using biotechnology, the humans genetically modify the local firelizards to be giant, flying steeds that the “renewable air force” rides. The genemodded dragons also have psychic links with their riders, which forms when the dragons are hatched and select humans “impress” themselves onto the creatures.

Dragonriders aren’t warriors; they are protectors. Pern experiences a seasonal weather pattern called “threadfall,” where deadly spores from a neighboring star fall to the planet, destroying everything in their paths. Unless, of course, the dragons can zoom around and burn the threads before they hit the ground. Guided by their trusty humans, the dragons protect all the people of Pern from the terrible thread.

They also have sex. And when dragons have sex, their riders – in constant psychic connection with their mounts – have sex too. This means a lot of “whoa I didn’t want to have sex with you but now that our dragons are having sex damn let’s do it” kinds of stuff. In addition, the most common types of dragons, the blues and greens, only get impressed by gay boys (and occasionally straight girls). So: Lots of gay psychic dragon sex. This strange scenario has meant that Pern’s large and talkative fandom has spent many years debating the sexuality of dragons in discussion forums and at conventions like the Weyrfest at Dragon*Con.

In her infamous essay on Pern’s renewable airforce, McCaffrey responded to fan speculation by talking a little about how dragon/human sexuality works:

In the Beginning of Dragonriders of Pern™, females rode green or gold. Males rode blue, brown or bronze. (I made it easier for myself in the beginning by remembering that Boys impressed Brown, Bronze or Blue, and Girls impressed Gold and Green.)

Since greens are females and tend to be ‘loving’, they mated with any dragon they fancied. When not enough girls elected to stand on the Hatching Grounds after the first disastrous Plague, males with feminine personalities Impressed green dragons. Blue riders, not to mince words, tended to be gay with masculine temperaments. Browns, who were not so inclined to mate with a green’s rider, made an arrangement so that two pairs of riders were involved in a green’s mating.

The dragons act in the way they were bio-genetically designed . . . While the main and most important application of the [telepathy-enhancing substance] Mentasynth was to increase mental function and innate empathy in the ‘dragons,’ a secondary use was to allow the newly hatched young dragon recognize the most suitable symbiotic partner. At hatching, the dragon recognizes by the sweat pheromones the appropriate sexual partner. Therefore the dragonet, just out of its shell, would approach only the male or female candidates exuding the proper pheromones for its basic sex type.

The green dragons are particularly sensitive not only to the mental empathy of possible candidates but also to pheromones.

McCaffrey’s dragon sex scenario is probably the most highly developed in the world of science fiction, but it’s not an aberration. Jane Yolen’s young adult Dragon Pit series explores the dragon reproductive cycle in great detail, and the psychic human-dragon bond does involve romance. Similarly, Christopher Paolini’s Inheritance series explores dragon sexuality and romance. Main character Eragon’s dragon Saphira is the last female dragon alive, so the issue of mating and reproduction is unavoidable for her. There is even a psychic dragon sex subplot in the recent Captain Marvel Annihilation series.

Several years ago, dragon sex became one of the most hotly-debated topics at the book-oriented World Fantasy Convention when a publisher handed out excerpts of Janine Cross’ Touched by Venom, the first book in her intense, harrowing Dragon Temple Saga. The excerpt, which describes a dragon-keepers’ ritual on an alien planet, includes a scene where young adepts are beaten with dragon-venom laced whips. Because the venom has aphrodisiac properties, the result is a bizarre parade where young dragon-keepers are marched through the streets covered in blood and brandishing giant erections. Unfortunately, it wasn’t the greatest excerpt to hand out: Con-goers found it laughable when they read it outside the context of the rest of the series, which is about a peasant revolt in an oppressive monarchy.

So why does dragon sex inspire such passionate debate? Why, indeed, does dragon sex even happen at all in science fiction?

There is one obvious answer, which is that dragons represent sex because they are enormous, fiery, beautiful, uncontrollable creatures of fantasy. The urge to have sex is one of those giant, burning desires that is particularly difficult to slay. It’s also an urge that is fueled by our fantasies. So there’s a kind of no-duh analysis of dragon sex, which is nevertheless true, that says simply that dragons are metaphors for sexual desire. This certainly explains the zillions of pages of Otherkin slashfic on the internet.

But of course everything is always more complicated than that.

Let’s consider the role that dragon sex plays in books like Yolen’s series or Pern – both of which have large young adult audiences. In his book Killing Monsters, comic book writer Gerard Jones talks about why kids are drawn to stories about monsters. He says it’s because kids identify with what it’s like to exist in a world ruled by the whims of giant creatures and megapowerful humanoids. Though Jones focuses on why kids like to watch monsters engage in violence, I think a similar thing might be said for why young adults might also be fascinated by giant creatures having sex. Sex belongs to the exotic world of adults. It’s something that young adults are aware of, possibly in internet-enhanced detail, but it’s also not something most of them are experiencing firsthand. So it makes a certain amount of sense that young people might identify with characters for whom sex is something they’re connected to mentally, via the acts of creatures more powerful than themselves.

Philip Pullman explores this idea in young adult trilogy His Dark Materials too. When his young adult characters finally have sex at the end of the series, they begin by petting each other’s animal daemons. These daemons follow every person around, acting as external representations of their feelings and desires. The same way McCaffrey’s characters sometimes express the sexual feelings of their dragons. In both cases, the smaller creatures act out the desires of larger ones.

Dragons are a simple metaphor for sexual desire, and they may also evoke the way young adults feel about sex. But those assertions still don’t entirely explain way dragons function in the venom cock scenario from Janine Cross’ Dragon Temple Saga.

I would suggest that the dragons in Cross’ novels are something like the worms in Dune. Cross’ dragons don’t have much of a psychic connection to their riders – they are more like animals, and so to the extent that they communicate telepathically it’s not much of a conversation. Not only do these dragons provide a drug that fuels a thriving black market economy (like Spice but less useful), but their eggs are a major source of nourishment to the people of the kingdom. And the fastest way to get around is by riding a flying dragon. So dragons are a cornerstone of the kingdom’s economy, crucial for food and transport. That’s why Cross depicts dragons as being hoarded by the ultra-rich. A major part of the peasant revolt involves redistributing access to the dragons.

Cross is doing something tricky with her dragon sex. She’s talking about those uncontrollable, giant forces that I mentioned earlier in connection with Jones’ book. But instead of her dragons standing in for adult sexual relationships, they stand in for the often-abusive relationships between aristocrats and peasants. She uses weird scenes of these dragons jabbing their venom-laced tongues deep inside our heroine’s special spot to show us how peasants are debased by their aristocratic overlords. At the same time, the peasants are made complicit in their degradation because they crave the high they get from the dragon venom. So Cross’ dragons stand in for the overwhelming desire people have for power over each other. Power that gives them the right to enslave, rape, and rule over other people.

Of course, sometimes a dragon is just a dragon. But dragons and sex often go together in science fiction because it’s an inherently metaphorical genre. SF stories about fantastical monsters are often fables that contain messages about our own world. A perfect alloy of beauty and violence, the dragon is an enduring figure for the power of sexual desire – and for the way power often finds its most brutal expression in sexual acts.