Mother-in-Law wants to help 10-year-old son in the shower. He usually takes a bath when at home, and he does that on his own though DH sometimes checks on hair-washing. DS didn't ask for help, but MiL said she'd go in the bathroom with him and help in wash his hair, etc. I said, no that's not appropriate. She is annoyed with me, and says she always does when he stays there. I think it's massively inappropriate. AIBU?