When you go shopping with a guy. Could be your father, brother, son, friend, boyfriend whatever.
If he puts on a pair of pants and tells you they are to small. But you are sure they are not it probably is code for my balls are getting crushed or are at least uncomfortable so if we buy this I will never wear it.
Yes I might have been in this situation more than once

with a few of the categories listed above
Ending with at least 3 perfectly fine pants still in my closet that my step mother bought for me since she thought it was about the money. There was no way I was going to be rude and even less chance I was going to spell it out.
As for shopping in general
There is very much a reason my one sister is my favorite person to shop with and one is if I say no for whatever reason she doesn't push any further for me to buy it. She has great taste and is just brutally honest in how stuff looks and is a safe female perspective so I don't look like a

. And when I am fed up with shoping or at least shoping for myself she gets that.
For reference obviously this is just my experience others might feel different.