I've never been to the YCMA, but back in the 80s when I was in high school and a still a teenger and "working out" was a fairly new concept for mass America, my family joined our local "health spa" where they had a gym, raquet ball, sauna, pool, etc.
I remember almost every time I went into the showers they were "private" with curtains, but more often than not, you'd catch good glimpses of older guys' big fat dongs swinging free in the shower in various state of "big floppy soft" to full hard on. They didn't seem to hide their dicks, but discreetly show them off to other guys, including younger guys like me.
When I used to go into the jacuzzi, 90% of the time, it seemed the guy next to you had a hard on underneath the water and many times older guys, I am sure married or str8/bi, would jack me off under the bubbles - not to completitoin (would have been weird to have the cum floating to the top), but for a good long while - I was sorta scared, so I just got hand jobs from older guys, I would never grab their dicks - even if I wanted to, cause some of them looked HUGE, like 8.5-9" thick. But most guys, honestly, were much smaller 5-6" range.
Related story: years later when I graduated from high school, one of the married/str8 guys from the gym who jacked me off in the sauna somehow located me at my college and showed up unannounced at my freshman dorm. I was 18 at the time - looking back this was dangerous, but I went with him to his nearby motel and he ended up sucking off me in the shower and later I fucked the shit out of him repeatedly in his bed. He kept calling me every now & then after that throughout my freshman year, but I didn't return the calls - it was more of one-time spur of the moment thing and I was still not quite "out" at college, so wanted to keep a DL profile.