Accidental Marriage/Playing With

Basic Trope: Somebody finds that a seemingly innocent action means they are now officially married.

Straight: Kevin shares a drink with the chieftain's beautiful daughter, and then finds out that it constitutes a marriage ceremony in her culture.
Exaggerated: Kevin nods politely to the chieftain's three beautiful daughters, and then finds out that it constitutes a polygamous marriage ceremony in their culture.
Logical Extreme: A marriage custom in which all marriages are arranged by a lottery-type system, and even those who know the system perfectly are surprised on the day when their number comes up and it's their time to get married. E.g., every three months there is a ritual feast attended by all members of the tribe, and there is always one single man and one single woman--the unsuspecting future groom and bride--who randomly get a wooden fertility doll in their piece of pie.
Justified: The culture in question is very isolated, and is not used to dealing with people who don't know their ways - nobody thought to warn Kevin, and Kevin had no way of finding out on his own.
Inverted:
- Kevin is already married to the chieftain's daughter, and accidentally does something which constitutes a divorce.
- Alternatively, Kevin intends to marry the chieftain's daughter. In order to do so, however, he must complete a series of long, difficult (and occasionally ridiculous) tasks, which is the marriage ceremony in their culture.
Subverted:
- Kevin is told that according to tradition, he accidentally got married... but he's quickly reassured that nobody really follows that tradition in modern times, so he's in the clear.
- Kevin is about to do something that would count as a marriage. His friends try to stop him, only to discover that he's in love with the chieftain's daughter and wants to marry her according to her own customs.
Double Subverted: ...only, that was before they knew it was the chieftain's daughter he'd done it with. For chieftain's daughters, following tradition is still a definite requirement.
Parodied: When he sees the amazingly beautiful chieftain's daughter, Kevin starts doing every weird thing he can think of in the hope that he'll trigger a custom like this.
Deconstructed: Kevin's accidental marriage raises questions of cultural clashes, the role of tradition, and the way that these things can shape the lives of individuals. Kevin is shown to resent the way his Unwanted Spouse follows him around, while the chieftain's daughter is torn between respecting the ways of her people and the fact that her marriage will obviously be unhappy.
Reconstructed: Even though Kevin and the chieftain's daughter are both upset and unhappy to begin with, they decide that it would be silly to let something like that dictate their future lives, and sit down together to work out how they want to deal with it.
Zig Zagged: Kevin is told that he has accidentally married the chieftain's daughter... but then he admits that he knew what he was doing, because he had fallen in love with her... and she admits that she was counting on that, because she wanted a ticket out of the village... except that the marriage isn't valid because they forgot a crucial step... which makes both of them happy, because the events of the episode have caused them to change their minds.
Averted: Kevin leaves the village with his new bride, only to realize that it was all just a sham and that she was really after something else.
Enforced: The writers want to give Kevin some sexual tension with the chieftain's daughter, but since she only shows up for one episode, they need a way to skip past all the normal romantic build-up.
Lampshaded: "You'd think they'd have mentioned that in the guidebook, wouldn't you?"
Invoked: Someone deliberately sets out to trick Kevin into an accidental marriage.
Exploited: Someone wants Kevin's real love interest to dump him, so they make sure she gets word of his "marriage" to the chieftain's daughter - not mentioning, of course, that it was accidental.
Defied: Kevin makes sure to learn about any unusual customs this culture might have before he goes.
Discussed: "If this was one of those wacky shows with weird situations, me giving this girl the thumbs up would result in an accidental marriage somehow! Perhaps her culture takes it as a sign of marriage."
Conversed: "I suppose Kevin is getting used to these accidental marriages. This is only like the third one he's been in."

Wait--going back to Accidental Marriage means I have to marry you? Fu-