it is completely normal for people to over eat while stressing out. it's a good think that people eat while stressed, some people stress out and DONT EAT AT ALL. don't worry about what others think, especially your "friend", they are not your "friend" if they can say hurtful things like that.
It’s better for you to give him an example of what to do and how to tell if the tub is clean, maybe even do part of it for him and show him the correct way.