Beyond the body, how can one objectively draws the lines between mine and yours?

I suspect "space/matter" belongs to whoever is more "responsible" (and more "conscious")… which for me, seems kinda subjective.
Currently, the line appears to be based on whoever draws it first or has the power to enforce it.
Ideally, all lines should be consensual. But I wonder if "space/matter" between you and me is "just" an eternal dance of the all becoming everything and everything becoming all..
(Anyways, I always try ground myself by acting from is "true".)