It becomes an issue of professionalism. You did the right thing by saying nothing in that situation. Letting out something like this in a professional context risks your career. If you met her in a pub afterwards and had a chat that would be different - you are not at work. However, when you are doing your work and trying to maintain a professional demeanour...

She did take a massive risk in asking, mind. UNless she noticed more than the choker. Because I know many women who wear them and aren't submissive or even know about the lifestyle.

I am working on the invisible ink membership cards and secret coder rings that all Lifestylers will wear to show who we are to other lifestylers