I am working on a horny comic whose plot revolves in part around a note with a postscript written in a language that the protagonist can only read when she is super aroused and I think this is the best excuse for hiding information from the reader I have ever come up with.
If only, I'm just writing it in a font full of nothing but dramatic swooshes that happens to be kerned so that it overlaps itself a lot.
You should include a challenge to the audience to get horny enough and see if they can translate it.
Hopefully reading the comic will do it! And also the protagonist translates it once she's horny enough due to her tits starting to expand uncontrollably.
I'm a grumpy queer dragon lady and this is my quiet cave for me and some friends.