tell them the truth .... I'm following them!
oh, I just came to people watch....with a big smile
I say I'm buying food. Lol
I'm shopping duh I'm in a supermarket diptard
Supplying my cupboard with alcohol
Getting food to eat and stuff.
I say, "and what are YOU doing here?" so maybe they hear what a goofy question it is
Tell them I am looking around for future targets.