@SixInch & King,
We have a triangular shape bath tub, and there is where I bathe with my 2 sons, it’s not overcrowded.
When time comes, just like I introduce him to jackinworld, I will introduce TP instead of telling him about PE and size, let him judge by himself and learn from all of you, just like me.
I never thought that bathing together with our children has any relationship with culture, I know not many people do the same in my country, but it’s just a matter of personal education and relationship I want to keep for my boys.