Heya! The best answer I can give you is a maybe.
I initially planned for it and have the sprite ready (albeit no CG). But most of the feedback I received said the story is already good as is. So, if there's gonna be NSFW stuff, I don't want it to cause a tonal dissonance and compromise the quality of the story.
That being said, I still want to write one and pass it on to beta readers. If it's approved, then I'll include it in the next (and final) update.
Hopefully, that answers your curiosity ^^