blank-face
To stare at someone who is obviously wrong, lying, inappropriate, or asking you something you will never answer. The blank stare continues until they realize their mistake and the awkwardness reaches fever pitch.
So, he said he called, but since there was no record of this on my caller id, no missed calls on my cell, and no message on either phone, I blank-faced him until he admitted that he had meant to call me but hadn't actually called me.