NTA. I have girls, and am a female, but both girls have seen me naked many times. They walk in while I pee, shower, dress, etc.

With my mom and brother, it was the same. My brother and I were constantly invasive on my moms space, naked or not. Sitting and chatting during a pee, during a shower; barging in on her when she was changing. I think it’s a very natural thing, honestly. The fact that someone could sexualize it and make it something it’s not is disturbing. It’s nothing but innocence. A child doesn’t see it the way we do, to them it’s just a body and parts, nothing more. It’s a body, it’s their mother. Your husband is being over sensitive.