Inkfinger's Melvelous map gave me the idea for this one. You stumble upon a restroom that has not been cleaned in many years. You hear strange squishy noises coming from the stalls. This does not bode well.
That's hilarious. However, why does the biggest stall and the one next to it have double thick walls? Unlike the rest? Also, I don't see the point of the 3X3 huge stall (bigger than an Ogre!) but with a little tiny door. I would look into the wood framework type things from Woodhome.
Even though the door is open terrain there is a way. Add a wooden wall where the door is located and switch the wall from blocked to open.
The scenario itself mirrors real life restrooms in many parts of the United States. Many times it is better to relieve oneself in the woods by the highway than in restrooms that time forgot. Attached is the one you requested Flaxative.
Glad to inspire. I like your take on the idea. Seems like the kind of thing one could actually expect to find in a bathroom. Very true to life. I had flashbacks well playing it. You might consider making a small portion of the bathroom flooded or something, that might be interesting, and also very much like things I have seen. With my own eyes. My scarred, scared little eyes.