''and she has the gall to stand right in front of me (literally inches) as I try them on''
I would consider making a wince and/or hand to the nose gesture as my head goes past her vagina. If I was in a particular mood I would continue by saying, "You should see a doctor about that."
She replies in a snippy voice, "See a doctor about what?"....in a sincere voice, "Feminine odor."
I'd hang around for a few minutes, even buy the shoes if I didn't want them, just to see the...