Source of the outburst:
Kirk: "You've got your peanut butter in my chocolate!"
Spock: "You've got your chocolate in my peanut butter...Sir."
Kirk: "Well...Get your Vulcan hands outta my food!"
Spock: "Sir, you're behaving rather irrational."
Kirk: "And I say that you're a freak! And you need to be off of the bridge and placed in a circus sideshow!"
Kirk: "Right next to the dog-faced boy!"