>>95930775
For aesthetics and themes (pic related), you can go as far out as you want, and you can even stuff your fetishes into your work (see H.R. Geiger). I'd argue it makes it that much more unique and authentic.
The issue is when you directly involve your players in your fetish. If the reason you're describing a vore scene to them or making them piss into a bridge troll's mouth is to just get your rocks off, don't fucking do it