Related Clues:

• What putting one's finger to one's lips may mean
• 'Shh! Don't tell anyone!'
• "Shh! Don't tell anyone!"
• 'Keep this between us' ... or hint to this puzzle's circled letters
• "Don't tell anyone!"
• Words that sometimes follow 1-Across
• "I can't tell"
• 'I can't tell'
• "No telling"