Problems with Parents/Nudity
My 11 year old son still undreses infont of me. He shares a room with his 5 yr old brother if I am in their room with his brother and he needs to change he just undresses in front of me. I not uncommon for me to see him naked on almost a daily basis. We are both comfortable with this situation, how ever my sister was visitng from away with her 5 yr old son, we were both getting our little ones ready for bed when my 11 year old walked in and began to undress. I was ok with it but my sister thought it odd.
Truthfully, I understand your sisters reasoning. It is one thing to be undressing in front of your mother (more on that later), but something all together different to underess with anyone else in the room.
First of all, there is the 'modesty' issue. Most children by the age of 8 or 9 have a problem with someone seeing their 'private parts'; even mom.
Second, it is one thing to do something with immediate family (if you are all in agreement) but
would you really like the next door neighbor seeing your son naked? If he is allowed to do it
there could be a day when he is doing it in front of the wrong people. And that could be dangerous.
Children need to be taught right and wrong---the right time something is acceptable and the wrong time. In gym showers, at home in the bedroom etc is right. At school in the locker room when alone with the janitor, at a neighbors house in the living room-NO. Get the idea?
I am surprised that your son doesn't get embarassed with someone outside of the immediate family 'seeing' him without clothes on; but that is something you will need to explain to him. I would be concerned with a possible predator being in the wrong place and your son not knowing what to do.
Hope that I explained it well enough and you understand that embarassment can also harm a childs ego.