SC - I wouldn't presume to tell anyone they aren't 'allowed' to share their personal lives and my annoyance was brief, just an inital reaction to possibly being outed against my will. None of us had any idea that there was a family connection at her workplace but now that we know and she understands that I'm not openly poly, she respects my desire for privacy. I never told her she wasn't allowed to share the joy of her new relationship with anyone, I only expressed a preference for privacy after the fact, simply by asking that she not share my husbands last name around the workplace so my aunt doesn't find out just yet. I have no issues with the 'fairness' of that request and neither does anyone else involved.
Being introverted, defined as being 'shy', means that I don't readily strike up conversations with people so I'm unlikely to just come out and tell people I'm poly. I'm trying to understand how the connection wouldn't make sense.
After reading this reply, I realize I'm feeling a bit defensive about your comments. Not sure what's pushing my buttons exactly, but definately cause for some further reflection on my part. Thank you for the insight though!