It seems like everything involving FJs and TPs has a mothering, finger-wagging overtone. At least the FPs and TJs get to have some sexual tension. Maybe there's some sexual tension if the FJ is semi witty and not clutching her pearls, fanning herself, and oh dearing about anything that comes out of the TPs mouth. More often than not I think the mythology and lore surrounding this is the FJ tries to get the TP to "grow up" and mature and take responsibility. Oftentimes, the FJ is an overbearing, ballbusting, status seeker and the TP is a schlumpy but good-natured guy or still wants to rock out with the band or follow his dream of being a hardcore rapper. In this incarnation the FJ will makeover the TP but he will eventually resent the person he's become: a TJ. Conversely the TP gets the FJ to loosen up and learn to laugh and enjoy life or some other such nonsense after she breaks the heel of her $750 pair of shoes in the rain and they fall in a muddy and coolant-filled puddle laughing hysterically. At best, the FJ is long-suffering and patient, always there to clean-up the TPs schemes gone awry. The TP may also be beaten into submission so thoroughly by the FJ that he becomes "Yes, dear" and asks the FJ what color and pattern of underwear is acceptable for him to wear.
FP/TP I think is far less severe mostly seeming like the laid back couple who are lovable goof-ups. Irresponsible but that's OK! Each thinks the other is a cool gf or bf or wife, husband, or partner. Problems only arise when the extroverted judging world impedes upon their lives by asking them to mow their lawn because an unidentified animal attacked a neighborhood child. (Un)fortunately for them it was the FJ/TJ's kid and they intend to prosecute to the fullest extent of the law. If the child survives, he (yes he...he is an FP who was in the process of running away from the TJ/FJ home. The lack of warmth was killing his soul and he just got cut from the junior varsity Golf team) will write the next great American novel based on his upper-middle class but void existence. He now resides in Soho, NYC with his ambiguously classified "life partner" who is also a writer. His memoirs are now a major motion picture starring Kate Winslet and Joaquin Phoenix. He doesn't give interviews, please contact his literary agent.