Maybe you can settle this debate. I have a white mug with tea stains on the inside. I know the stain can be completely removed with baking soda, just haven't done it.

My wife's claim is that the mug looks disgusting and it would be wildly inappropriate to serve a guest a mug like that.

My claim is that the mug is clean and the stain is harmless and purely cosmetic, and a guest would not care.

Probably we are both projecting so we need some objectivity. What would you think if you came to my house and I gave you a white mug with tea stains? WIBTA? 
