What The???

I had a woman looking at my work this morning, bags that I make with my own fabrics, stitch the begeebers out of and then create lovely handles for, and she proceeds to try and disassemble the bag!

She was shocked that I would be horrified, her comment was "well don't you take things apart to see how they are constructed and to see if the construction is quality or not"? Well actually no I don't, and I informed her as much and since the bags were silk I was a little bit more than put out. She kept claiming that she wasn't doing this to try to copy my bags - yeah whatever get your mitts of my stuff lady.

So the twenty million question is how does one politely tell someone to get their mitts off of your work??? I'm not always known for tact and I know this so I tend to keep my mouth shut so as to not dig myself a grave but come one why would someone do something like this??? Personally I find the behaviour not only odd but inconsiderate - I just don't know how to tell this to people when they behave in such a manner.