Rugby is not only open to nudity but encourages it.
After training or playing, undressing together in the locker room, getting naked in the communal shower and under the hot water (sometimes not hot at all) was as much of a team building experience as any of coach's speeches.
We are all big lads and banter is intrinsic to rugby life, and with banter comes lots of naked horsing around.
In some games we would end up so full of mud that the whole team would hose down outside the locker room block, just quickly taking off our kit and holding the boots while a teammate mercilessly power washes your naked ass and run for the shower as soon as the mud is off, that's how casual nudity is.
The coach/coaches shower with the team only when needed (rainy days and certain celebrations)
Some of the new lads need a crash course in manliness and being naked around teammates, but they never struggle more than a day.