Possible Clues:

• 'Let this be our little secret' ... with a hint to 18-, 23-, 50- or 54-Across
• ''It's a secret . . .''
• Secret-teller's intro
• ''Confidentially . . . ''
• ''Confidentially . . .''
• ... 'got' or 'tell'?
• Don't tell people exciting women need beauty
• Don't tell anyone -- like most of the characters in Youth Training Scheme
• Location of what divides us, not going any further
• UXS