This has happened to me twice now as a very particular and intentional thing.
When in a group but talking directly to person A, person C interrupts loudly steps between us facing me and tells me their opinion very forcibly. Completely blocking my view of person A who is now looking at C's back. When I step or lean to the side to make more of a triangle and talk to A again C steps to the side to block us.
There must be a name for this. It is infuriating and I don't know how to handle it. Getting infuriated doesn't help of course.
In both cases person A and B are doing work at our home and person C (and D) were brought in as additional. They clearly thought their opinion was the most important and should carry the decision. I didn't.
I am not good at decisions and find it helpful to talk them through before making them. A knows that and is helpful and patient, but just stands quietly and lets it happen, which I don't blame him for at all.
It is obviously a thing. I just want to be able to name it and to stop it in its tracks rather than standing helplessly getting lectured.