When i was in high school, i never showered after gym class. Not sure how i managed to deal with my own stench the rest of the day. often, it did not seem like there would be enough time to shower & get to my next class, assuming i actually wanted to shower. I was always too shy to be seen by others, and somehow dealt with my own stench back then.
When I had belonged to a gym in my mid 20's, i finally did reach a point where i wanted to shower after my work outs and racquetball games. I had no interest in looking at other guys, nor would i ever have wanted to be caught looking at someone else. Especially with a lot of these guys being regulars you'd have to see practically all the time. I always looked down, showered for the minimal amount of time, covered myself with a towel promptly between showers & the locker.
Between the awkwardness i felt, the no attraction to men, and the exhaustion from working out / racquetball, i never really had to deal with erections in the locker room. Though I did spend time in the locker room's whirlpool / hot tub. So if you wanted to see me nude, that was your time. Most of the time, i had it to myself. If someone was already in it, chances are i bypassed it altogether.