I don't generally go to locker rooms or communal showers specifically to expose my penis but if I happen to be there I'm usually not one to shy away from letting other people see my private. After all, everyone in the room's got one.
Yeah, I've always had a degree of 'excitement' when exposing my privates to onlookers in the dressing rooms, especially when I see them getting aroused when looking at mine. Shameful? Naugh, just a bit naughty.
Sure. I've flashed in plenty of public places. When I lived in Monterey, CA. I used to flash this lady everyday on her way from work while she drove past my house. She could see me from about 30 yards. I eventually met her at the NCO club on Fort Ord and we had sex the same night. Later I told her the guy that flashes her everyday was me. She was kinda embarassed to admit she was turned on by both of me. Sorta like Clark Kent and Superman. You can't recognize superman without the glasses. lol