waking up after dreaming be incontrol of 2 bodys

many years ago i came across something which still confuses me to this day, it goes something like this:

sleeping -> wake up at normally between 2-4 am -> sit up in bed -> my brother across the other side of the room sits up as well -> i lay back down -> my brother lays back down like hes a mirror of me -> think nothing of it, take a drink and go back to sleep,
weeks later, same thing happens again but this time i sit up fully then as i start to lay back down i stop half way and watch as he does the same, i speak to him but there is no sign hes even aware or awake, i also discover when i wake up and roll over, i hear the same thing happen of the other side of the room from my brother, i also tested waking up and sticking my arm straight up in the air and was mirrored once again by my brother across the room, and again he was still not aware or awake at the time,

if anyone has any knowledge or opinions please feel free to share