Christmas Story, A - Where'd the Potatoes Go?
During the scene towards the beginning where the family is sitting down to eat dinner, Randy is told by his mother to "eat like a little piggy". So, gross out, he proceeds to eat his mashed potatoes like a pig and smears them all over his face, even into his hair. His face is plastered with potatoes! Then, we hear the door bell ring with the lamp delivery and we see Randy turn his head, while still at the table to look at the door. His face is perfectly clean after just seconds before that it was covered.