I work at a library, and we do put a romance sticker on the spine of our copies of "Outlander." The librarians who swear up and down that they "don't read romance" or "don't like romance" are all crazy about this series. It's one of those romances that flies under the radar. It is different from the sorts of romances in the paperback romance section, though, and I feel like the people who borrow the mass market romances are not usually the same folks who will read all of Outlander. Or listen to the crazy long audiobook versions of Outlander.
Now, Outlander has some outlandishly HAWT sex scenes, and you might be interested to know that Diana Gabaldon has a book all about writing sex scenes, titled I Give You My Body: How I Write Sex Scenes. It's $2.99 on Amazon.
I love the Outlander series and I think the authors short book of writing sex scenes would be fun to read and educational :)
"I Give You My Body . . .": How I Write Sex Scenes (Kindle Single) https://www.amazon.com/dp/B01HA4LFB6/ref=cm_sw_r_cp_apa_bKLGAbHTK4JZY
Miskatonic University
https://www.amazon.com/gp/product/B01HA4LFB6
The best $3 you'll spend all day.
I’m just leaving this right here for the writers in the room. Not really smut-related, more about writing sex scenes from both male & female perspectives.