private prejudice vs. public offense

My husband and i had to pick up my car at local Pep Boys. We decided not to use their service as it was too expensive. So we paid the diagnose/misc fee of $55 and my husband also asked for a spark plug kit.

We were speaking to each other.

"dear, can we afford another twenty some dollars?" 
I demurred him, "no, we can't. but of course, we can put
the charge  on our credit card and continue to incur jewish 
interest. And if we can't pay off the interest in our life
 time, our son can inherit our debt as a gift of life..."

Admittedly, it has been my private, very biased, totally without any scientific merit to credit jewish people as the sole inventor and pusher of interest rate fueled financial services industry. But i do not, to the very far stretch of my imagination would anticipate that our very low pitched private conversation can ignite a protest from one of the two Pep Boys' employees who served us at the autopart counter. She is a clean goodlooking, tall young girl. "Excuse me, what's your comment about interest rate? I am a jew. I very much take offense of your comment." I do not know how to respond to this gril who not only sell Pep Boys' autoparts but also police people's private conversation" and make her disliking of my personal prejudice a public protest before the other Pep Boy employee.

There is no excuse for her to volunteer telling me about her jewessness when it wasn't called for. Do i take offense of her sense of'being offended'? I do. Not only for myself, but mostly for her and for people like her.