Note: Only three people in the group (of about seven or so) knew about MBTI, and only ISFJ and your resident INFP knew about the cognitive functions.
INFP: *sitting on counter swinging legs while deep in thought*
ISTJ: Are you silently judging us all?
INFP: What? No, I’m a perceiver.
INFP: ISFJ’s a judger though! *points finger*
ISFJ: Bah, perceivers. My introverted sensing collects all the memories you forget about.
INFP: But my extroverted intuition collects ALL THE POSSIBILITIES. *sticks out tongue*
ISFJ2: Did you just stick your tongue out at her?
INFP: Uh, yes? This is a rather frequent occurrence when we get in arguments.
ISFJ2: Good to know.