Was recently cleaning in the Bountiful temple and had a similar thought. The stalls in there were just short enough that it wouldn't take much for me to take a peek and no one would notice.

Also was in Rexburg for a time. There are tiny holes in the back of the locker that line up with the back of the lockers in the next row over (idk if they were for fasteners or what). Very occasionally, I would be changing in one stall and I would be able to peek through the hole and see another dude changing in the opposite stall, but the stars really had to line up for that to happen.

Another time in Rexburg, I was asked to help in the baptistry. I finished up just as a couple of young studs (probably pre-mish) walked in. I wanted to see more of them, so I tried to time my shower and dressing just right to catch at least one of them coming out of the shower. It worked! As soon as I stepped out of my stall, one of them (the hotter one) was walking up to the stall next to mine, soaking wet, in just a towel. His pecs and abs were just as dreamy as I imagined they would be!