Rake over the ashes/the past - Idioms by The Free Dictionary
rake over the ashes/the past
rake over the ashes
To revisit, bring up, or spark the memory of something that happened in the past, especially something unpleasant. Now, now, there's no need to rake over the ashes, that disagreement we had happened a long time ago.
rake over the ˈashes/the ˈpast (informal, disapproving) discuss with somebody unpleasant things that happened between you in the past: When they met each other again, ten years after the divorce, they both tried hard not to rake over the past.