Personnally, Inever eat when I'm reading hentai. For one I don't want to get my doujins dirty, and second I don't want to get my computer dirty, and third my hands are busy most of the time.
I guess ive eaten food while reading eroge but never during an ero scene. Since h manga is basically ero scenes all the time I dont eat while reading it. And now Im reminded of the seinfield episode about eating while having sex. lol