[I2S1] CD: The silent treatment, huh?
Their mouths are moving in a silent display of blatant ridicule, the lack of sound ringing louder than any spoken jeering or cajoling ever could.
They think they are so clever. Well, they've got a big storm coming: you have MASTERED the art of LIP READING as a part of your specialized skill set. And also you have your means of making them talk. It is a matter of honor after this slight.