No, I have no problem flashing my package to other guys. I've gone naked infront of friends on a dare before (friends who ran from where they were sitting to get the best view). I'm very comfortable in gym shower settings, group or otherwise, if there are curtains I close them only not to be so obvious about showing off my big dick. But I don't feel the need for a towel or anything wrapped as I'm walking around the locker room.

Interestingly, I have one friend who has stated that he would not shower in a group shower setting with me because my 'mr. perfect' body and endowment (he hasn't seen, but he is certain I'm hung, which I am) would make him uncomfortable.