sometimes people writing about fantasy gay sex are right, actually. just found out that sword oil CAN be used as lube. listening and learning.
As someone who write fantasy, including the gay one, I’d very much love to know how you found that out.
Well... I'm the kind of person who will start reading a fic on AO3, say "that can't be right," and go down an hour-long Wikipedia hole about historical lubes.
Most natural plant-based oils may be used as lube, though they're messier and not as good as modern water-based or silicone-based lube. Just remember that oils aren't good with latex — but your knights probably aren't using latex condoms, anyway.
Historically, a common sword oil was linseed oil, which is natural, plant-based, and food-safe. So, again, a fine choice.
Other historical options include other plant- or vegetable-based oils, which are probably fine. Some also used animal oils though, which is not fine and can lead to infections. Avoid that shit 🙅
For traditional Japanese swords, choji oil was used, which is made from cloves. High concentrations of clove oil can be toxic, so you HAVE to dilute that shit — 1% concentration or less. Once diluted though, clove oil is considered safe and can be used to treat and soothe anal injuries. It also has a numbing effect that could help with rough anal sex, but your ass would hurt like a bitch after the effect wears off.
A lot of modern sword oil is just mineral oil, which, while not plant-based, is food-safe and is actually recommended for use in enemas because it's safe and long-lasting. So while it's not great for vaginal use because it can irritate the skin there, it can be pretty well-suited for anal use.
There are a few modern sword oils made from machine oil and motor oil. Those should not go in any orifice whatsoever 🙅 Always check the label before using improvised lube.
Anyway, I hope that helps! I hope your knights enjoy their fantasy love-making ❤️