Side by side then they are behind.
I have noticed this several times now. We may be talking as a social gathering whilst watching our kids side by side, shoulder to shoulder with a small expected gap.
As we talk we speak straight ahead of us and then sometimes gesticulate and then turn our heads to look at each other whilst speaking. It is mixed up this way like a normal, organic conversation.
However, I have noted on a few occasions that the other person can end end diagonally behind me. Like at 8 o clock on a clock face to my 12 o clock. When they are there I have to really rotate around when speaking.
Why do they make small micro adjustments and end up almost behind me?