maybe they haven't quite picked up on why you're bringing it up - that is, to own up to it. it might not be clear, i don't know how you present it.
in a case like yours i'd let as little time as possible pass to own up to it (though my own actions don't always reflect it). everyone is different, i recently let half a year pass before owning up to something, and everything turned out fine.
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הייתי צוללת עכשיו למים
הכי, הכי עמוקים
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וזה הכל אהובי, זה הכל.