live on borrowed time
To live or exist in a temporary and/or tenuous position, which may come to an end suddenly and abruptly. Accidents and disease can strike so unexpectedly that it feels like we're all living on borrowed time.
live on borrowed time
Fig. to exist only because of good fortune; to live on when death was expected. The doctors told him he was living on borrowed time. You are living on borrowed time, so make the best of it.
living on borrowed time
continuing to survive against expectations (used with the implication that this will not be for much longer).