To burn your bridges is to destroy a relationship you might have needed. Try not to burn your bridges.
It is nearly always advice against, since the cost usually falls on the person leaving. The picture is an army destroying the bridge behind it so retreat is impossible.
1phraseburn your bridgesTo destroy a relationship you might have needed.
“Resign politely rather than burn your bridges on the way out.”
burn your bridges is a phrase.
Practised in Idioms