What else?
Of course we all bath and shower nude, there is no other way. But do we share our bath or shower with someone? I always shared the bath with my late wife. Her children (my step children) would come in and talk to us while we bathed. Now I share my shower with my friend. We soap and wash each other.
I remember that we showered together the second time we were together, we had returned from the beach, chatted a bit and then showered before dinner ... we did some other things as well, but I think that this is not the group to talk about that ;)
I grew up taking baths with my sister until she reached puberty. After that I started showering with my buddys when we could since were already showering together at school after gym class. I have continued to save water when I can!
I used to when I went to visit my dad, my half sister was a few years younger then me, we used to do everything together from a early age , it wasnt a problem we saw each other nude and bathed together, I then never saw her for about 2 years, i was about 12 she about 10, we didn't think anything different and went to bath together