They're grrrape!

Simon experiences his first grape.  His world will never be the same again.  Grapes.  Are.  Awesome!

Awesome enough to go all "sneaky bun" and try to steal River's grape from her.  Here he is trying to tip-toe his way over while attempting to look nonchalant about it.
Don't worry, the epic grape theft was averted by herding Simon away so River could happily munch her grape in peace.