This always happens. I go out shopping during my lunch hour and people assume, just because I’m wearing a shirt and tie, that I must work in the shop. Within 5 minutes of entering Next, I had fended off three separate inquiries of, “do you work here?”
It occurred to me later that I could have taken advantage of this to amuse myself. I could easily have replied in terms such as, “yes I do work here, and could you kindly leave as we don’t want your sort in here,” or, “You want those in a 32 inch waist? We’re being a bit optimistic there aren’t we? Ask at the counter for our out-size ordering service,” or a simple, “SECURITY! WE HAVE A SUSPECTED SHOPLIFTER HERE!”
I’m too nice to do anything like the above, but it’s an interesting idea for someone with anti-social tendencies to try out.