That doesn't work at our house. SO expects an honest opinion and so do I. So she never asks me if an article of clothing makes her look fat. She asks me if I prefer outfit A or outfit B. By the same token, I expect honest answers when I cook something and ask if she likes it.
Same here. If I can't get my husband to tell me that an outfit makes me look fat, who am I supposed to ask? If the danged dress makes me look fat, I want to know so I can wear something else.