I was on the swim team and was used to wearing speedos at the pool and being naked in the locker room and showers. My teammates were obviously the same way. Anyway after a few years on a team you get used to it then start to be pretty comfortable with your own body (I definitely don't have the bigger dick; it's average to below) and take advantage of situations where you can get naked often.
Guys and gals who wanted to do lifeguard training would go to a public pool and work with the red cross or a similar group. For the few years I did it, usually a few friends from the team would join. Most of the guys and gals who would do lifeguard training were around my age, some a little older. I knew a few of the guys from my sports team too.
We obviously wore trunks during training, but the locker rooms after training were always an interesting mix of men. There were dudes like me and my teammates, who had conditioned ourselves to let prude behaviors go, and others who weren't. Anyway a guy from my team and I were talking about the training, where we were going to work for the summer, end of school stuff, and we dropped our shorts like always, toweling off, grabbing some shampoo for the shower. We turned around and saw two guys from a different school carefully pulling their shorts off while towel dancing. My buddy Nick nodded his head in sadness and just went over and started talking to them butt naked, an attempt to try to get them out of their shell and show them it wasn't a big deal. Nick was a well built dude and had a big dick, but he wasn't an intimidating guy by nature. We knew these guys from meets in the past but never had long conversations with them. Anyway Nick was just asking where they were going to work and where they were going to condition over the summer, I remember conditioning with one of the other team's guys who was there so I chimed in to help Nick out, dropped my towel on the bench and walked over naked to them too to join the chat.
The guys from the other team had never had an interaction like this before so they seemed pretty intimidated at least at first. One of the guys clearly wanted to use this as an opportunity to break out of his own shell so he unhooked his towel and just started drying off his hair, letting his boys air out freely. He did it right as he could take the conversation, I think it was just a good opportunity for him to take action and break out of his prudishness so to speak. After a minute or so of chatting Nick offered to continue the conversation in the gang shower, we were going to shower anyway. He and I walked back to grab some shampoo and sure enough the other dude who dropped his towel followed us in. I think it was his first time showering naked without a speedo on. I asked his teammate if he was joining but he said he was in a hurry or something. He didn't join us.
When we were in the shower I asked if his team showered naked or in speedos. He said only a few seniors showered naked, most of them stayed in their speedos. I remember saying our team always showered naked, and we wondered which other teams did the same after practice or meets. We added it was good to go into the shower with the speedo, but to take it off and wash it out independent of our body. Nick then added that showering naked at away meets sometimes made other teams intimidated, especially if it was on their own turf so to speak. The other guy from the other school said he was going to join the join the senior ranks the next week and just start showering naked, adding that clearly it's better for a lot of reasons.
Only now in my older years am I realizing I was probably trying to be a little alpha, a little assertive. Nick and I weren't trying to condition anyone, I think we were just enjoying what we could do and trying to show others that they could too. For the one dude, he totally broke out of his shell. When I had a meet that next year with that dude's team I saw him showering naked afterwards, totally comfortable. I think he appreciated that opportunity and never looked back since then.