...Short for "oh don't cope". When someone is actively in the coping phase, that's when you hit 'em with the "oh don't", in other words saying "oh don't cope"
*in a rainbow six siege match* *person 2 misses all their shots, rook turns around and pops them*
Person 2: "broooo my bad papa i'm tired rn thats why I missed" "can't win 'em all papa"
Person 1: "oh don't"