Bible Study Presbyterian style

I belong to a Women's Bible Study at my church which happens to be Presbyterian (PCUSA) by affiliation with a membership which is generally pretty liberal. Our weekly discussions tend to wander away from the assigned topic from time to time. Today we discovered that each of us in the group has at least one close relative or friend who is quite conservative and literal when it comes to their interpretation of the Bible. We all agreed that there have been many times when we have, or should have, bitten our tongues in respect to their opinions. One member of the group, Ady, one of the kindest people I know, declared that it is a wonder we don't all have cancer of the tongue, considering how many times each of us has had to bite ours. Personally I should bite my tongue more often. As a case in point, at Easter dinner this past Sunday, when one of my guests told the table that she had just been to see "The Ark Experience" in Kentucky and that it was huge and very impressive. I have seen pictures provided by another friend who visited the same site and I agreed that it looked very impressive. I should have stopped there but some times my mouth seems to just keep running even though my mind has disengaged. I said that I really don't believe that the Noah's Ark story in the Bible is literally true. With two grandchildren (who go to Catholic school) and two pastors at the table, my comment was met with resounding silence. What could I do? I not so subtly shifted the conversation to a whole different topic.  Will I never learn?