Harry Potter and the Prisoner of Azkaban - Lollipop
When Harry decides to go to Hogsmeade alone he uses his Invisibility Cloak once he steps out of the cellar. Then he snatches a lollipop from one of the students and starts licking it. How come the lollipop shows, but not his face? Does he lick it through the cloak? It should have been hidden, shouldn't it?