In 2010, a trans woman named Mira Bellwether from Iowa published an underground zine, titled Fucking Trans Women. The tome, a self-proclaimed "80-Page Giant," is entirely devoted, as its title suggests, to the subject of sexual intercourse as trans women (and their lovers) experience it. Because this subject matter is so rarely discussed, and Bellwether's publication was so artful and raw, the zine became immediately iconic.

Bellwether's goal in producing Fucking Trans Women was, as she writes in the opening, simple: "I wanted to talk to other trans women about how we like to fuck." She believed that the community would benefit from dialgoue about the specific sexualities experienced by different trans women. This meant recognizing the lack of information about how trans women view their bodies, and how our partners may not know where to start.

Because Bellwether's experience with sex is largely related to her experience as someone with a penis, the zine is heavily focused on pre or non-op trans women's bodies—and that, she wrote, is just the start of the conversation. She emphasizes that "just because what's in my crotch looks like a penis doesn't necessarily mean that it works like a penis." This radical idea is fundamental to the entirety of FTW as a text, but perhaps best exemplified by a portion of the zine dedicated to a little-known sexual practice that Bellwether refers to as "muffing," or fingering a trans woman.

Muffing, as Bellwether calls it, is just one of many sex acts in FTW; it stands apart from the rest because it involves penetrating orifices that most people don't know exist. In order to understand the act, you first need to understand the anatomy involved: Bellwether describes the act as "being [finger-]fucked in one or both of my inguinal canals," which are, as she puts it, the "twin 'pockets' that are situated in the groin above and behind the testicles and scrotum." Generally speaking, inguinal canals are the canals that the testicles descend from—the same pathways that balls get sucked back into when you jump into a pool of cold water. Bellwether refers to these parts of her body as her "cunts," and uses that chill term interchangeably with their medical name.

In order to penetrate or fuck your inguinal cunts, you need to locate them inside your body. This can be challenging, because, unlike your anus, the entrances to these canals are enveloped by flesh. In order to locate them, FTW advises users to take their hand and feel upward and behind their dick. This is where you'll find the entrances, which Bellwether says are "initially about the same diameter as a finger but will stretch considerably." She advises first timers to "start slowly" and to be careful.

According to Dr. Curtis Crane, a urologist who specializes in gender confirmation surgeries, muffing is both safe and quite pleasurable; several of his patients have asked him about it, and in all his years providing medical care to trans patients, he's never seen a trans girl or cis guy come in with a "muffing injury," he assures Broadly. "I don't think anyone has to take any safety course before going for a muffing party or whatever they want to do," he adds.

Dr. Crane affirms that it is totally logical to finger your trans cunts. "Anatomically, the ilioinguinal and genitofemoral nerves—which both give sensation to the genital area—are right there in that canal, so that would feel good," he says, explaining that there are two "rings" of the inguinal canal. One is "superficial," meaning it is on the exterior of the canal, where it enters into the scrotum. The other ring is deeper inside you. "Right where you're putting the finger in, that's really superficial, but if you were to follow it all the way up then you would actually go intra-abdominal," he says. However, that last act is neither advised nor feasible: "It would be impossible to go through the skin that far, but if you made a hole you could dissect all the way up to there."

You can push your testicles into canals, as trans women sometimes do when they tuck their dicks. (The practice extends outside the trans community as well: "Traditionally, sumo wrestlers would put their testicles up in the same inguinal canal right before they wrestled," Dr. Crane notes.) Or you can penetrate the canals with your finger by "inverting the scrotum"—like a finger condom made of scrotum. "The technical term for this is 'invagination,'" Bellwether writes. For some trans women, this is the ideal form of sexual gratification.

"[My sexual partners] could stroke [my penis] all they liked and it wouldn't do much," says Hannah, a trans woman who has experience with muffing. Hannah adds that she would use her hand to muff herself during sex because engaging with her "penis" in the traditional sense simply didn't turn her on. She's since had a vaginoplasty, so she doesn't muff anymore, but she says that was her primary form of masturbation "way back when."

Muffing during partnered sex is a different ballgame, mostly because so few people have heard of it

"I miss it, actually," Hannah reminisces. "Besides using the space for tucking, it probably did feel sexier and was easier to arouse than actually having a vagina is now—not that I don't love not having a penis to carry around." She prefers the dry nature of muffing; you don't have to lube up, and unlike a vagina, inguinal canals don't get "wet" because they're inside your body. "I miss being able to masturbate without wet wipes," she laments, "though it's hardly the end of the world."

Tyler, a trans woman from Baltimore, says she first heard about muffing in early 2013, at the start of her transition, when a friend gave her a copy of Fucking Trans Women. The practice wasn't new to her, but the name was. "I'd been doing it since I was a kid," she says. "I just discovered it poking around one day. It always felt natural to me, but I think I felt a bit of shame around it, so I never talked about it until I read FTW."

Bellwether's groundbreaking zine educated trans girls across the country. For Tyler, FTW gave a name to a practice she'd discovered on her own, and also illuminated the details of what she was actually doing to her body. "I had no idea what the inguinal canals were called before I read that, and I'd always wondered about them," she says. "These weird, not quite hole-shaped holes have been such an important part of my sexual development and sense of self, and hardly anyone realizes that they exist."

This is part of what makes FTW so cool. There's practically nowhere to go to learn about sex if you're a trans girl and don't want to just jerk off or do things to your butt. Fucking Trans Women puts sexual practices that are overlooked in the mainstream (and certainly not taught in sex ed classes) on paper for the first time. "Honestly, I've gotten a better sex education by being an out disabled trans bi-dyke who likes to fuck than I would've ever gotten in school or otherwise," Tyler tells Broadly.