Our dgs always has a shower at his own house & his perfectly capable of looking after himself & taking himself off to bed.
When he stays with us he still wants a bath at night & still quite likes dh to be in the bathroom with him so they can have water pistol fights. Obviously my dh is not in the bath with him! He is 8. Is this still appropriate for my dh to be in the bathroom with him? When he's with us we don't want to make him think bodies are something to be ashamed of, but at the same time he should be learning to have personal boundaries & privacy regarding his own body.
After having 2 children of our own you'd think we'd know the answer to this, but after 30 years we can't remember what age our own dc stopped this. I think they probably had more privacy by now.