Postnuptial Disagreements is a crossover Fan Fic for ''Manga/{{Sekirei}}'', ''VisualNovel/FateStayNight'', and ''LightNovel/FateZero''. It is written in first person from the perspective of Meriwether Archibald El-Melloi, the son of Kayneth and Sola-Ui from Fate/Zero, who survived an AU fourth Heaven's Feel. And he's pretty much [[ChasteHero exactly]] [[HopelessWithTech what]] [[SmugSnake you]] [[JerkAss would]] [[InsufferableGenius expect]].

On a trip to Japan to research his parents' role in the Fourth War, Meriwether finds himself stuck in the middle of the Sekirei Plan after Benitsubasa wings herself with him. Naturally, he leaps off the [[JumpingOffTheSlipperySlope slippery slope]] with the zeal of a true magus, making the Sekirei Plan a whole lot bloodier in the process.

Benitsubasa soon finds herself [[OnlySaneMan trying to deal with the insanity that her Ashikabi has unleashed]]. And get laid. Which isn't [[ObliviousToLove as easy as it sounds]].

Postnuptial Disagreements is also noteworthy for a surprising amount of [[CharacterDevelopment character development]] over the course of the 'fic.

It can be found [[http://www.fanfiction.net/s/8078340/1/Postnuptial_Disagreements here]] and [[http://forums.nrvnqsr.com/showthread.php/2269-Postnuptial-Disagreements-%28Sekirei-crossover%29 here]].

!! This fic provides examples of:
* AntiHero: Meriwether. Though he might qualify as a VillainProtagonist, depending on your interpretation.
** Unsurprisingly, Meriwether thinks of Richard from Theatre/RichardIII as a hero, and not as a VillainProtagonist.
* AnyoneCanDie: Many of the 'deaths' are little more than the defensive-comas of Sekirei terminations, but as the finale gets closer, [[spoiler:there are ''a lot'' of Level Five terminations.]]
* BigBad: [[spoiler:Karasuba]]
* BrainsAndBrawn: Meriwether thinks initially of him and Benitsubasa as this, but it turns out they are far more equal than he thought. The existence of magic is a shock, but Meriweather notes (even before he's fully accepted her as an equal) that she's very good at taking his fantastic abilities and accepting their results without needing to fully understand how they're possible in the first place.
* CharacterDevelopment: Meriwether AND Benitsubasa, though your mileage may vary.
* CombatPragmatist: Meriwether learned from the mistakes of his father in the last Grail War.
* [[spoiler:EarnYourHappyEnding]]
* FirstPersonSmartass
* ForWantOfANail: The specifics are never specified, but Meriweather mentions Kiritsugu Emiya's destruction of the hotel Kayneth was using during the Fourth Grail War, which means that Lancer was killed either in that event or quickly enough afterward that Kayneth never launched the attack that resulted in Kiritsugu destroying his magic circuits.
* HopelessWithTech: Meriwether
* ImADoctorNotAPlaceholder: Kochou, Meriwether's [[spoiler:undead hacker.]]
-->''"I'm a computer expert, not an oracle."''
* InnerMonologue: Magus that he is, Meriwether compensates for his limited external monologues by providing a running commentary on everything from assassination techniques to [[ArsonMurderAndJaywalking home furnishing]].
** LeaningOnTheFourthWall: This is commented on by [[spoiler: Uzume]] when Merry uses a spell so that they share consciousness.
* TheJuggernaut: Miya
* MagicallyBindingContract: A favorite strategy of Meriwether is to manipulate or blackmail others into one with him. [[spoiler:Later, Higa and Miya use it successfully against him.]]
* MasterPoisoner: Meriwether
* MeddlingParents: Kayneth takes this [[UpToEleven up to eleven]].
* NobleBigot: Meriwether
* PairTheSmartOnes: One of the main reasons why the relationship between Benitsubasa and Meriwhether works is that they both are smart people who seek other smart people as partner.
* PapaWolf: Dozens of Sekirei and Ashikabis won't stop Kayneth from retrieving his son. Later on, [[spoiler:Kiritsugu]] makes it clear that the qualities separating Meriweather from his parents are the sole reason that he lets Meriweather even ''associate'' with [[spoiler:Ilya]].
** [[spoiler:When Kayneth is starting to [[TheyWouldCutYouUp vivisect]] Benitsubasa, it's very, ''very'' clear that he's ''not'' happy about the apparent fact that his son's mind was altered as a part of the Sekirei-Ashikabi link.]]
* SparedByTheAdaptation: Not only do Meriwether's parents survive the Fourth Grail War, but Kiritsugu and Ilya live much longer than in canon. The same [[AnyoneCanDie can't be said]] of quite a few members of the Sekirei cast.
* TheyWouldCutYouUp: They really would, Benitsubasa. [[spoiler:And Kayneth even revives her after she was terminated so it would be a vivisection instead of an autopsy.]]
* WhatMeasureIsANonHuman: Part of Meriwhether's CharacterDevelopment is to accept Benitsubasa as an equal and opposing the treatment she would receive at the hands of other magi.