The whole point of going to the gym in the first place is to tone up the body to be able to work that last muscle in the wet area with likeminded fit men. There are so many stories to tell...
I remember once when I was in my mid 20s, chipping away at my BA in the late 1980s in Austin. I drove my then-girlfriend's car to a community college PE class that I was just using to rack up a credit. The only reason why I did not drop the class was because the shower scene afterwards with otherwise straight guys was superior. We're talking four of us hanging out naked under the warm water of the gang showers for the better part of an hour shooting the shit, showing chub and boner and leisurely stroking a few times a week.
Cruising a local gym where I go to shave my nuts, there are occasionally developmentally disabled guys who use the facilities. One guy, an adult nothing special to look at, would always look at my dick, so I'd let it harden up for his gaze. Often times I'd see him come into the sauna. I'd work up a hardon in the steam room and then head over to the sauna. I'd unwrap the towel from my waist and my hardon would slap against my navel, then sit on the level below him, against the wall, knee up to block the general view. He was able to see my throbbing hardon and would stare intently. I'd then give my favorite exhibitionist line, "this does not bother you, does it?" He'd quietly say no and then repeat what he'd been taught, don't touch in public but would continue to eat up my boner with his eyes. His sense of wonder was amazing. Neither of us touched, but everyone should be able to be horny. I think several times he went into a private shower and rubbed one out at the thought.
I tend to not wanton wank in gang gym showers, preferring to keep it just hard enough to be hard, sometimes pretend to try to hide it for plausible deniability. Over the decades the experiences of exhibitionism and cruising I've done in gang gym showers is the fuel for ample wank sessions. Sadly, gang gym showers are an increasing rarity these days. Often times, cubicle curtains are replaced with doors that make it so much more difficult to show off. Not to worry, there are always steam rooms and saunas for such exhibitionism.