Interesting discussion.
I have body issues in relation to my weight and height. I'm skinny, and I don't like it. And that is the only reason I have any issue with group nudity. I love my dick, and I've had many compliments about it, so that wouldn't prevent me from using a locker room or showering naked with other guys.
If my body shape was more to my liking you'd have a hard time keeping me out of locker rooms!
My best mate is the opposite. He has a great body and goes to the gym several times a week. He has no problem showing off his abs and flexing his muscles, but he's really paranoid about his cock.
He's told me he doesn't get naked in the shower at the gym, but claims to have no problem with nudity. He's even commented to me before now about a guy he works out with who is hung like a horse and walks around the showers with it flopping about for all to see. He's told me he really wants to see the guy hard too, just to see how big it is.
But he has nothing to be worried about himself. We wank together and his dick is great! His Mrs has no complaints either.
It did take a while for us to get to that point, and the first time we wanked together he hid his dick from me the whole time. He did it all in his jeans.
I've come to the conclusion that things are vastly different in locker/shower room norms between the US an Europe. I've seen loads of discussions in recent years about how the US is becoming increasingly shy about the dick. Urinals are increasingly partitioned. Showers are replaced to be separate stalls.
In the UK I think we're continuing on with the support of nudity. We seem to have fewer qualms about showing our dick and appreciating other's.
And unlike the US, in the UK it is becoming more common to state that you're bisexual or bi curious as a teen, IMO. Bisexuality is definitely on the increase here, with more younger people willing to discuss it and openly explore it.
There is still a divide between intellect in relation to it though. The more common, sport label and gold-jewellery wearing younger person (or "chav" to us Brits) is still as ignorant as ever. But the "other", more sensible, well-rounded youth, are being more open about sexuality and choosing to leave their options open so they can experiemnt more freely.