a liar hiding beneath a layer of deceit
They’re like a rat in a trap, they won’t squeak until you’ve got the whole trap around them and the door is locked.
He didn’t admit he was cheating until I showed him the video and locked the door.
She wouldn’t say a word until I put her in a headlock and threatened to call her mom.
He only confessed when I had him cornered and the lights were off.