There are a couple of people in the family who can’t communicate well. For entirely different reasons.
One thing they have in common is they don’t listen to what others are saying and they try to put in their two cents' worth based on what they imagine the other is saying. Probably based on notions they already have in their head. It's confusing to the person they are trying to talk to and either frustrating or amusing to any observer (depending on your level of detachment).
Sitting there listening to them try to communicate with each other is an even more bizarre experience.
It’s as though each is in their own world, and they don’t even realize it. They just keep talking past each other, misunderstanding everything the other says, thinking they are talking about the same thing, and the conversation goes further off track the longer they talk. I've tried to step in and get them both on the same page, but often it's pointless. Just let them run their course. They'll end up making plans and neither one knows what the other thinks they've agreed to, and then it's up to others to untangle it later.
It's like trying to have a conversation with a statist.