Show of Hands

Just say no.

I wouldn't just say "yes" or "no". I'd take a second to look her over and give a considered response, like "it looks fine, but this line right here kind of draws your figure out a little bit". I've never gotten in trouble for this, it's always been an "okay thanks"

Neither. I give her a straight-up honest answer. "No". Because [that] doesn’t make her look fat.