Cup Cakes Lost

I brought in cup cakes to my second hour class to add a real sense of Wayne Thiebaud's cake painting and originally would use these cupcakes as still life. My junk food driven students want to eat those cupcakes more then to paint them. Eventually at the end of the day, someone took one of the packages from behind my desk and according to the icing dropping on the floor, they ate them! On one hand, I feel angry because the student crossed the line stealing, and on the other hand, I am sad about students making fun of their teacher.