Answer: INSECRET

AnswerCrossword Clue
INSECRETUndercover
INSECRETHow backroom deals are conducted
INSECRETCovertly
INSECRETSub rosa
INSECRETConfidentially
INSECRETClandestinely
INSECRETUnbeknownst to others, bug picks up pair of recruits (2,6)
INSECRETWithout the knowledge of others.
INSECRETOn the quiet
INSECRETOn the sly
INSECRETBehind closed doors
INSECRETBug holds musical note without being obvious about it (2,6)
INSECRETOvertly
INSECRETOn the q.t.
INSECRETHow some lovers meet