For the most part we don't, and when we do, we keep it to ourselves. Let me explain: Humans compare...everything. Logic dictates that we make sense of our bodies and selves through comparison with others. For example, if we didn't compare, we'd think we're all good looking. But we're not; that's why we invented Hollywood for good looking actors, AND politics for ugly actors.
We compare height and weight, we compare hair color, nose size and neck circumference. Tooth color, fingernails, complexion, eyebrows, knees, crotch and waist size. Some of these things are socially acceptable and shared openly. Others aren't.
In other words, in the locker room you may hear, "Dude, you got that tall ass height. You're a lucky man. I'm only 5' 7", see?"
But you won't hear:
"Dude, your penis is huge, it bends sharp to the left, but none the less, it's thick as sh*t and dwarfs mine, see?"
When it comes to the human form, adults are taught not to look at each other's privates. It's considered sexually offensive, aggressive, provocative or plain rude -- gives people the willies. Besides, there's so much else guys like to talk about in the locker room: football, combat sports, biceps, body fat and cologne.
lol @ sneak a peek!