Toilet Seat Divorce

""A Roman divorced from his wife, being highly blamed by his friends, who demanded, 'Was she not chaste? Was she not fair? Was she not fruitful?' holding out his shoe, asked them whether it was not new and well made. 'Yet,' added he, 'none of you can tell where it pinches me.""

- Plutarch in the first century AD, making this Older Than Feudalism

Situation where a marriage is threatened to be broken up over a suspiciously minor setback or argument, sometimes venting complaints about behavior which just surfaced. This can occur even after the spouses have jumped numerous hurdles in the relationship to be together, and usually smells of the inability of writers to do other plots or as cheap extension. From more capable writers, it's more of a Rant-Inducing Slight, the proverbial straw that broke the camel's back and unloaded years worth of pent-up frustration.

The archetypical example, which gives this trope its name, is the cliched argument over leaving the toilet seat up or down.

Slightly more tolerated for teenagers who break up, since you expect them to be overdramatic.

In Real Life, before the advent of no-fault divorce laws, it wasn't unknown for a couple who mutually wanted to separate to use these sorts of things so that one or both could claim mental suffering in order to have the legal justification for the divorce.

See also Minor Flaw, Major Breakup, Rant-Inducing Slight, Disproportionate Retribution.

Comic Books

 * In the Mad Magazine parody of Mrs. Doubtfire, the judge grants the main character's wife a divorce because he left the toilet seat up.

Live Action TV

 * Ross and Rachel from Friends. Since the series depended on them being separated in order to work, their break up was quick and completely difficult to understand. Ross cheated on Rachel (read cheat as: slept with someone else after Rachel suggested they should take some time), and even after Rachel forgave him, she couldn't be with him because "she would know that he cheated on her with that other woman". This doesn't stop her from wanting him back, which makes all this pretext more useless.
 * Dr. Wilson from House had what seems to have been an example of this trope, given how he and his ex get along when they end up back together. The only difference the second time around is that House convinced Wilson to actually speak up instead of let the irritation build up to Rant-Inducing Slight levels.
 * Also,
 * In Spin City, Mayor Winston and an ex-girlfriend from his college days had apparently been driven apart by an overly competitive tennis match.

Music

 * Played for Laughs "Weird Al" Yankovic's "Albuquerque": After getting married and having kids, one random night, his wife says to him, "Sweetie pumpkin, do you want to join the Columbia Record Club?" Not ready for that kind of commitment, they broke up and he never saw her again. But that's just the way things go in Aaaaaaaaaaalbuquerque.

Radio

 * A sketch in That Mitchell and Webb Sound has a woman and her husband half-heartedly arguing about his having an affair. Turns out she's really just itching to pick a fight because she hasn't gotten over the far worse trauma caused by him leaving the fridge door open a week earlier. She had to throw out almost a whole quiche!
 * And don't forget the milk! All that milk!

Theatre

 * In Mary, Mary, Mary makes her ex-husband Bob recall that he started packing his bags one night when he got into bed with her and she said, "Okay, let's get those colored lights going." His excuse for having divorced her over this "very small straw" is that he had been having a bad day.
 * The title of Barefoot in the Park comes from an argument (which leads to a threatened divorce), nominally about how Paul didn't want to take a barefoot walk in Central Park.

Western Animation

 * In one episode of The Simpsons, Mr. and Mrs. Van Houten have a breakup that's precipitated by one spouse losing a game of Pictionary, though this incident was really only the Rant-Inducing Slight for long held deep grudges.
 * An episode of Arthur has D.W. and Arthur imagining their parents getting a divorce over literally spilled milk.
 * Not a divorce, but Gazpacho in Chowder had a falling-out with his mother over proper tooth-brushing technique.