Everyone has their own opinions on who the ultimate OTP is, but to figure out which one fanfic communities sexualize the most, you have to turn to hard data.

A new analysis from Witch Sandwich, a site that proudly boasts itself as “your source of nerdy fanfiction stats,” reveals which “ships” (imagined romantic relationships between fictional characters) are the smuttiest. The fanfiction deep dive is based on longform stories posted to Archive of Our Own in 2015. The fanworks site uses a rating system for fanfiction, broken down into General Audiences, Teen And Up Audiences, Mature, and Explicit: only suitable for adults.

Turns out, “slash” fanfics (featuring two male characters) were typically more explicit than those that were “het” (heterosexual pairings) or femslash (involving two women). The top 15 most explicit ships all featured guy-on-guy action.

The most explicit pairing is that of Dean and Sam Winchester, the hunky paranormal creature-hunting brothers from TV show Supernatural with a mildly homoerotic relationship. Its status as number one is not surprising: the Supernatural fandom is known for being more than a little bit extra, so much so that there’s a documentary about it in the works, and its obsession with the brothers becoming sexually involved is so well-known within the fandom that fanfic about it has its own name: wincest.

Supernatural’s show creators have been accused of exploiting its LGBTQ viewership by queerbaiting: writing in even more subtle allusions and GIFable interactions, throwing more fuel to the burning loin-fires of the fandom. Jensen Ackles and Jared Padalecki, the actors that play Dean and Sam, are the second smuttiest pairing, with 61 percent of the 173 RPFs (real person fiction) written about them containing explicit material.

An interesting observation by post author “Mrs. Pekkala” is that het and femslash tend to be rated Mature rather than Explicit. For the curious, femslash pairings with the highest percentages of mature ratings are Delphone and Cosima from the TV show “Orphan Black,” and — another incestual sibling duo — Anna and Elsa from the Disney movie “Frozen.” Het pairings with the most mature content are rhyming couplet Daryl and Carol from “The Walking Dead” and Caroline and Klaus from “The Vampire Diaries.”

Pekkala states that the difference in ratings could potentially reflect a bias in the way that “explicit sex” is perceived when it involves two males within the fanfic communities. But then, it’s also important to consider the most-used tags for slash, het, and femslash, which sheds light on more specific aspects of the stories. While anal sex was the fourth most-used tag for male-on-male stories, tags indicating blatantly sexual content didn’t appear until the seventh place for femslash and tenth for het.

Read the detailed data breakdown at Witch Sandwich.