I am a male nanny and have been one for years. In terms of kids and bathing it really varies depending on the situation. Some parents have their kids bathing themselves, even with no supervision, at age 6, while others still do some of the washing close to middle school age! For the kids I've babysat, bathtime etiquette will depend on what the parents and kids are comfortable with, and their age and gender.
I have bathed girls I babysat for before, but they were both under 6. I know some people here are going to see issue with that, but why is that these women can post about washing a 12 year boy old on genitals, and I can't talk about washing a young girl? It wasn't sexual and I had the girls do their own private areas. I never wash the private area of any child who isn't a baby. I feel that is best left up to the parents, and if it's skipped one night by me during bathtime, that one night won't make it dirty and kill them.
Out of the boys I watch, 90 percent of them prefer to have me keep them company during bathtime. The ages vary from about 5-12. I usually don't do any washing for the older ones, but they like to have somebody in there to keep them company because "bathtime is boring". Most of the the time there is usually a bit awkwardness the first time I see them undressed, but they usually get over it pretty quickly. It's a boy thing, and boys are usually very casual about their bodies around other males. It's actually kind of a bonding experience. They tell me it's no big deal and it's like having a
Big Brother there, and nobody cares if their
Big Brother see's their birthday suit.
They love me to sit in and chat, but as they get closer to middle school age, I am mindful of what is appropriate and what is acceptable. I start sitting in and chatting less and less and just occasionally checking in. I slowly phase myself out of the bathroom routine. After all, why does a 12/13 year old need supervision during bath/shower time? That's not to say that if they called me because they needed a towel, or I had to get something from the bathroom, I wouldn't go in. But there comes an age where you need to let kids bathe or shower alone, even if they ask you for company (which some of them still did).