Squelching A Nosy Person

Recently a member complained about a nosy neighbor who asked her what she got in the package that just arrived.  Admirably, she replied NONE OF YOUR BUSINESS.  Today I tried a more complex, time-consuming way to discourage a nosy tenant who always peers into my grocery cart to see what I am buying!  Literally she almost puts her head in my cart!  Today when she did this, I decided if she was that nosy, I would EXPLAIN why I bought every one of the 20 items in my cart.  I kept her "trapped", telling her "Underneath the salad is a bag of apples, and do you see I bought such and such, and oh, yes, I always buy this because..... She is so dense I wonder if she even caught the sarcasm. HEE HEE HEE