I have something that's bothering me

My sister brought up to me that my son should start taking baths/showers by his self he's 7 and I still take both with him I don't see the problem but this isn't all the time we take them together he's scared of something I'm not sure what it is when I asks him he doesn't know why he's scared of the tub but I don't like what my sister said that we are weird taking baths and showers together 😕 help I need answers 😢😢