be living on borrowed time
From Longman Dictionary of Contemporary Englishbe living on borrowed timebe living on borrowed timeSURVIVEto be still alive after the time that you were expected to die She’s been living on borrowed time for the last year. → liveExamples from the Corpusbe living on borrowed time• As long as Moira was around, Tamar was living on borrowed time.• But now, as long as they existed, he was living on borrowed time.