I have a feeling I posted this a few years ago, but I'd kinda forgotten about it till yesterday, so if I'm repeating, who'll know?
My local college gym locker room (which was enormous. It was like a 45 second walk from the forest lockers to the open showers, a walk I gladly took each time with my towel over my shoulder and my cock and balls swinging as I walked) was undergoing renovations, so they shifted the men to a small martial arts room. This room had a padded mat and probably 30 lockers. It had a bathroom with one urinal and one stall. It also had a two-head shower room possibly 14x14 feet. In some misguided attempt to provide unneeded privacy, someone in the gym mgt bought a shower curtain rod with a plastic curtain and those plastic rings that suspend the curtain from the rod. They placed this curtain between the two shower head areas.
A little mischievous sprite in me decided this was unnecessary, so every time I took a shower, if there was no one on the other side, I would remove one ring and put it in my bag. I went to the gym maybe 3 times a week so within a couple of weeks, there were only two rings, each at the far end. I found this amusing. At one point, I think I removed the ring closest to the shower head, so the poor curtain just hung limply from the far end.
At that point, the mgt noticed and replaced the rings. Well, would believe it? Somebody (oh, that'd be me) removed the rings one by one again!
This happened for like three cycles, and I amused myself by imagining the conversations in the office:
"What the fuck is happening to all the rings for the shower curtain?"
"What?"
"They keep disappearing."
"WTF?"
" Yeah, I guess somebody's taking them for some reason."
"Uh, I think the reason's pretty clear."
And for my final flourish, after they'd bought new rings 3-4 times, suddenly all the stolen rings reappeared, provided by yours truly. Imagine the confusion in the office while I laughed silently to myself. Of course, the trouble with these "pranks" is that you never really get to SEE the results. Oh, well.
This shower room had two open entrances, one for each head obviously, and those entrances, normal door-sized, had curtains, so I figured if I went in and closed BOTH curtains, the guys who came to shower figured they'd have to wait, but I'm sure they'd be confused as to why both entrance curtains were closed where there was just me in there... but now that I think of it, they might have written it off to: "There's a shy guy in there and he wants total privacy." I can't recall that I actually did to that but....
One time I went in and closed my entrance curtain. The other shower was occupied and its entrance curtain was also shut. The inter-shower curtain was hanging by a few rings, and I could easily see the guy at the other shower thru the gap between the edge of the curtain and the wall. I "soaped up" (i.e., jacked my cock) to see what'd happen, and sure enough, he responded, so I got to jack him off in the shower, which was awesome, of course.