Related Clues:

• Tell-tale
• Go furtively - inform on another child
• Move furtively - tell tales
• Dishonest person
• Move furtively - informer
• Tiptoe, perhaps
• Skulking sort
• Behave furtively
• Sort of snake in the grass
• Sly person
• One going behind your back
• Underhanded schemer
• Crafty sort
• Crafty person
• Preview opener?