Question

(to) burn one's bridges When he was fired, Chad really felt like telling Lisa that she was a terrible manager, but he didn't want to burn his bridges.origin: This expression comes from the military. Soldiers dating back to the days of the Roman Empire used to burn the bridges behind them. This meant the Roman troops couldn't retreat; they had to keep moving forward. It also made it more difficult for the enemy to follow them.

Accepted Answer

to do something which makes it impossible to go back; to damage a relationship to such an extent that one can never go back to that person again

Idiom	(to) burn one's bridges
Meaning	to do something which makes it impossible to go back; to damage a relationship to such an extent that one can never go back to that person again
Example	When he was fired, Chad really felt like telling Lisa that she was a terrible manager, but he didn't want to burn his bridges. origin: This expression comes from the military. Soldiers dating back to the days of the Roman Empire used to burn the bridges behind them. This meant the Roman troops couldn't retreat; they had to keep moving forward. It also made it more difficult for the enemy to follow them.

Burn Bridges Back Roman One's Makes Impossible Damage