Both the Petrie and Helper households have intercoms, through which they can communicate with each other. When Ritchie is through playing with the one in the Petrie household he leaves it on. Rob and Laura notice this and are about to turn it off when they hear that the Helpers have also left theirs on, enabling the Petries to hear what they're saying. Against their better judgment, both Rob and Laura procrastinate in turning it off, and leave it on long enough to hear Jerry and Millie criticizing them. At their next get-together, at which Buddy and Sally are also present, the Petries drop hints while playing charades on how they feel about Jerry and Millie. The Helpers and Buddy and Sally notice something is wrong, not aware of what the Petries heard. After they've all gone home, the Petries again listen in on the Helpers private conversation, and this time hear, not criticism, but compassion and concern. Rob and Laura then realize they were too harsh in judging Jerry and Millie, and that we all say things in private conversation we may not necessarily mean.
We should all remember this when we hear someone talking away from the microphone. If we assume that others, not aware they're being heard, are always saying what they feel deep down, we must hold ourselves to the same standard. Who of us is prepared to do that? Who of us would want to be heard speaking in our most intimate conversations (issue: privacy) and then be taken to task for what we say, regardless of our emotions at the time we have spoken (issue: judging others)?