take into one's confidence
Trust someone with a secret, as in She took me into her confidence and admitted that she was quitting next month. This idiom uses confidence in the sense of “trust,” a usage dating from the late 1500s.
Words nearby take into one's confidence
take in,
take in good part,
take in hand,
take in stride,
take into account,
take into one's confidence,
take into one's head,
take into one's own hands,
take issue with,
take it,
take it easy