I don't think some like dear abby is going to have a very open or liberal view on matters such as polyamory since she is probably going to be fairly set in her way and old fashioned when it come so to relational situations that fit out of the old way some people view as "normal"
I had to deal with kind of the same situation this Christmas we went and saw my grandmother that lives about three hours away from us. it terrified me to no end, that someone in the family might ask me how my dating life is going but over the years the family has realized keeping my private life private is better.
and to be fair I know that if any of my grandparents ever were to fin out about the situation they would automatically compare it to adultery and call it final here and there. Its irritating cause it does feel like I am lying to them, and kind of faking my life to suite them....but people spend soo much time of their lives being wasted just trying to live up to people expectations of what they want to think of them....and it really quite pointless.