“Excuse me, where is the bathroom, because I don’t see a door?” I ask while still devoting considerable energy to fighting off what feels like someone shook a seltzer bottle and shoved it up my [butt].
She looks at me, bemused, and says, “Well, we don’t really have one.” At this point, she reads my mind, and preemptively continues. “Well, technically, we have one, but it’s really just for emergencies. Don’t worry, we’re landing shortly anyway.”
“I’m pretty sure this qualifies as an emergency,” I manage to mutter through my grimace. The turbulence outside is matched only by the cyclone that is ravaging my bowels.
I can see the fear in her eyes as she nervously points to the back of the plane and says, “There. The toilet is there.” For a brief instant, relief passes over my face. “If you pull away the leather cushion from that seat, it’s under there. There’s a small privacy screen that pulls up around it, but that’s it.”
At this point, I am committed. She just lit the dynamite and the mineshaft is set to blow. I turn to look where she is pointing and it makes me want to cry. I do cry, but my face is so tightly clenched that it makes no difference. The “toilet” seat she is referring to is the seat occupied by the CFO, i.e., our [freaking] client."

https://medium.com/@JohnLeFevre/the-roadshow-aka-the-worst-private-plane-trip-of-all-time-3eb88ab42b18#.uilwpetwj

P.S. there is some bad language