I like showing off in the changing room at the gym and sometimes, if its quiet and I let myself get a boner. I have seen a few other guys in the changing rooms with boners, so its not unheard of. I sometimes get my cock hard in the shower cubicle and then step out with it jutting out in front of my pretending that I haven't noticed, but mostly I will just stand naked applying moisturiser to my body, just to show off a bit, even rubbing some on my cock and balls!
I'm totally with you man, I like to get a nice full semi in the shower and then strut about the locker room showing it off. I also like to moisturise, I pay good attention to my cock when doing it. A lot of guys blatantly look, I've even seem some guys get hard watching - what a turn on!