Eating crumbs out of your partners bed?

I am always so peckish when I visit my boyfriend. He sometimes eats toast and pizza in bed, which consequently leave crumbs/crusts. When he goes to the kitchen or bathroom, I eat the crumbs that are left behind in the sheets. This morning, he unfortunately caught me and now thinks that I am "creepy" and "disgusting". I thought this was normal? What should I do to convince him that I'm not strange?