a blank
When the person you're talking to is so blank they might as well be a ghost that just stares at you like you're the weird one.
I was telling my friend about my day and he just nodded like I was talking to a wall.
I asked my brother how he was and he said 'fine' and then went back to his video game like it was a religion.
My boss asked me if I needed help and I said 'no' and then walked out like I was royalty.