NY Times Crossword
November 6, 2013
Jacob McDermott (adapted)

Each phrase below can be transformed into a familiar expression when it is used to answer the clue: "Let this be our little secret."

1. SAID IT NOT
2. CAN'T FOOL
3. TALKIN' TO
4. DON'T SCARE

Answer:

The clue "Let this be our little secret" can be answered by BETWEEN YOU AND ME.

Placing the phrases "between" YOU and ME gives the familiar expressions:

1. YOU SAID IT NOT ME.
2. YOU CAN'T FOOL ME.
3. YOU TALKIN' TO ME?
4. YOU DON'T SCARE ME. 

NOTE from JA: This clever puzzle, in its original form, used the following clues for the four phrases:

1. "Don't put words in my mouth!"
2. "I wasn't born yesterday!"
3. "Wanna start somethin'?"
4. "Ooh, I'm shaking in my boots!"