@understanding101, I read your original post and checked back to see how the discussion was going. I am very interested in the topic of how poly can seem/feel to non-poly family members. It was brave of you to post and I applaud that you were open-minded enough to join a forum and be vulnerable about how you felt.
I realize the orginal post is gone, but I'm glad to topic is back. I've spent enough time being poly and among poly folks, that I can forget what it's like on the other side - where anything other than monogamous looks deviant and strange.
If you haven't moved to private message, can you explain why you feel intruded on? Is the one person who regularly brings up the topic relating their everyday life or pressuring you into agreeing with him/her? How do they interact with you or your family that you find crosses your boundaries?
I hope you continue the discussion as I think there is a lot to share on both sides.