Scrubs Season 2 Episode 6

J.D.: Oh, I get it. Well, let's see how tough you are without your costume on. Go ahead and-and knock the folders out of my hand now!
Janitor knocks J.D.'s folders to the floor
Janitor: What costume?
J.D.: You weren't wearing a gorilla suit before?
Janitor: There's someone running around in a gorilla suit? What's he look like?
J.D.: A gorilla...
Janitor: No, it's not me.
J.D.: Well, then, why'd you knock the folder out of my hand?
Janitor: Because you asked me to. Here you go.
He puts his banana peel in J.D.'s breast pocket.
J.D.: I didn't ask you to do that!
Janitor: Yeah... that comes free with the folder knock.