Stingy....?

I was in the kitchen the other morning, and Mrs. Giver of Life was packing her lunch. She was searching all over the kitchen and finally I asked if I could help her find something. She looked at me and asked if I ate all the cookies. I laughed and said no, I laughed because she looked distraught about it. So I went to the den, which is right beside the kitchen, and asked Mr. Step if he knew where they were. He said no they were all gone. Mrs. Giver heard this and poked her head in and asked where they went. Once he realized that they were for her and not me he pulled a bag of them out of his lunch sack. 

This has me wondering why a grown man would be stingy with food when it comes to me. Telling me it is gone, or sometimes even eating it so there will not be any for me later. It really boggles my mind. We are not poor, and food is not scarce. So if anyone knows why an adult would eat food so others cannot have it, or hide it from others please let me know. I'm curious to find out the answer.