A few years ago I was staying at a hotel in Scotland that had a gym attached to it that guests could use. Was a really nice gym.
The shower doors were floor to ceiling frosted glass cubical style. The glass made it so you could tell that someone was in there, you could see the silhouette of a person but not much else.
Once inside one, the walls were also frosted glass and the partitions went up as far as my neck, so you could easily make eye contact with the guy showering next to you. With the glass though, the closer you got to it, the easier it was to see through. So if you were up close to it with your cock or your ass it would be very visible to the other person.
Honestly it was set up perfect for cruising and showing off. Unfortunately I didn’t get the chance to try it out, I did see a couple nice cocks drying off though.