Verified answer

If you think about it too much, you are probably gonna give yourself an erection, just relax.

Try to keep visibility to a minimum. Underwear off and towel on straight away.

In showers try to keep eyes up, no looking around and don't clench your muscles, that restricts the bloodflow = easier erection.

I wouldn't worry too much, the likelihood is that you'll be too nervous or shy to get an erection. If you do get one though, just act normal. Who is going to want to point out that you're erect? It means they were looking at your cock. What does that say about them?

It's a shame that you've gotten all the way to this age before using open locker rooms and showers with other guys. When I was young, we used them since elementary school, meaning all my classmates and I often saw each other naked before, during, and after puberty making it absolutely no big deal to see each other that way.

Simple nudity isn't sexual when you're used to it, so being gay or not really is irrelevant.

What is the problem, you don't want to get excited about being with naked guys or embarrassed about being naked. I guess for either situation just think of something else. Focus on raking leaves ir changing a car tire or something like that.

"now! I have to get naked for the first time! And be around others!"

Don't look. That locker room setup is the only kind I've ever known.