Charlie Brown's joy getting stomped on by another, unthinking character is becoming a common theme for strips. Just three days ago Snoopy "fetched" CB's golf ball in play, and Charlie Brown couldn't stand that either.
Could it be that Snoopy's disdain for the candy here results from Charlie Brown's harping and hawing over the idea that Snoopy will beg for it? The dog has
some pride after all.