Nudity has never been an issue in my home and I hope it never will be. My 14 yr old DD1 often showers with the 3 little ones, to help me out. DS1 (almost 18) finds showering with them strange but does it whilst wearing underpants. Both DH & I shower with the 3 little ones. I do not see a time in the near future where DS2 will feel uncomfortable bathing with his sisters. They're all more than happy to bathe together and it is great for me as it saves loads of time & water. My niece & nephew bathe with my kids when they're all together too. Niece is 3 & nephew is 2.