Ted: Robin Scherbatsky - will you be my backup wife?
Robin: A girl always dreams of hearing those words. Yes, yes, a million times, yes!
- An interesting variant is used in the My Little Pony: Friendship Is Magic fanfic "Relax". The protagonist and the prostitute he regularly sees make plans to marry assuming that he survives the war and she hasn't been either moved away, fallen for somebody else, or been bought as a personal Sex Slave. It's quite heartwarming.
- Brought up but ultimately averted in Romance and the Fate of Equestria. Twilight, still a Broken Bird from her previous relationship, isn't ready for another and wants herself and Donut Joe to be Friends with Benefits. As the hope of a relationship with her was the only thing keeping him in Equestria, he decides to go through with his plan to take a five-year journey with the travelling Bazaar, leading Twilight to propose this trope if they're both still single when the Bazaar returns to Equestria. Through further discussion, they realize that this trope would be too heartbreaking if only one of them was single, so Twilight instead suggests that they remain faithful to one another and stay in touch for the next five years, and get together at the end no matter what.
- My Best Friends Wedding where this trope, and the main character's attempt to wreck her best friend's relationship so that she doesn't end up being the Unlucky Childhood Friend form the central plot. She fails, nearly wrecking her friendship with the guy in the process.
- A variation in When Harry Met Sally: Harry and Sally agree that if either of them ever don't have a date on a national holiday, they will take each other to whatever party they're going to as a date. Sally eventually gets sick of this saying that she doesn't want to be Harry's "consolation prize". They get married about three months later when it becomes clear that they actually had feelings for each other.
- In Íverenskommelser by Simona Ahrnstedt, Seth has one of these with his New Old Flame Lily Tremaine. They're friends rather than lovers, but still decide to get engaged. But in the end, they break it up when Seth is reunited with Beatrice (the story's female protagonist) and Lily finds true love with Alexandre (with whom Beatrice had a similar relationship).
- Discussed and averted in A Brother's Price: The princesses are all very fond of their cousin, Cullen Moorland, and at least one of them would like have a fallback marriage pact with him. However, her sister points out he is too close a relative. As the the male Gender Rarity Value could lead to inbreeding, they're much stricter about this than most real life societies.
- In Happy Endings Penny is mentioned as having a marriage pact with Butt Monkey Shershow, who ends up getting married in the first season finale, prompting Penny to fake being engaged to not feel bad about her own singledom.
- Ted and Robin make one in How I Met Your Mother, which pretty much (but not entirely) marks the end of their Will They or Won't They? arc. Apparently the term "Ted & Robin pact" has entered the vernacular. This is discarded as of season 7, though the series finale has Ted's children encourage him to pursue her again after her divorce from Barney and the death of The Mother, so the implication is they eventually get together anyhow.
- Rachel suggests making one with Ross, who claims he already has one with Phoebe... who is the one who suggested it to Rachel in the first place, claiming she has one with Joey. By the end of the episode, they settled on Ross being Rachel's backup, and Joey being Phoebe's.
- A variant in another episode; Chandler suggests to Monica that if neither of them are married by the time they're forty, they could have a child together. (This was before they were dating). It doesn't go like he expected.
Monica: Why won't I be married when I'm forty?
Chandler: Oh, no, no. No. I just meant hypothetically.
Monica: Okay. Hypothetically, why won't I be married when I'm forty?
Chandler: No! No, no—
Monica: No, what is it? Seriously, is there something fundamentally un-marriable about me?
Chandler: (fumbles at back) Dear God, this - this parachute is a knapsack! (Rolls off of chair)
- Carla Noll in Reunion is Aaron's best friend and hidden secret admirer for years. She's happy to hear him say that if they're still single in a few years that they'll marry each other.
- In one episode of Frasier, it sounds like Roz is about to suggest one of these, and Frasier agrees to marrying her if they are both indeed single at the time. Turns out Roz was going to suggest they kill each other instead.
- In JAG, Harm and Mac agree to have a child together if neither have a significant other some time in the future.
- In The Office, Michael Scott suggests this to Pam (at least in terms of having a baby together) if they're still single in ten years. She shoots it down immediately... and, ever the salesman, he starts haggling. When he suggests that they do so if she's still single in thirty years, she thinks about it for a very long time and agrees.
- On Seinfeld Kramer proposes to Elaine that they marry each other if they're both still single at 60, and she accepts.
- Hudson and Mrs. Bridges - the butler and cook - of Upstairs Downstairs have this arrangement. In one episode Mrs. Bridges seems to have found true love and Hudson offers to release her from their friendly agreement. Unfortunately her beloved turns out to be a jerk.
- Murphy Brown has Murphy and Frank discuss the idea at a point when it seems like their romantic prospects are all but dead, but they let it drop and move on.
- Peejee proposes this to Davan in Something*Positive as a way to guarantee neither of them grows old alone, which she is especially worried about as even their regular group of friends has largely gone their separate ways. Davan refuses, promising he'd never abandon her anyway and shortly thereafter Davan meets Vanessa, whom he would eventually marry. It was the climax of a long bout of Ship Tease the creator had used to taunt the shippers who wanted Davan and Peejee together, since them not getting romantically involved is one of the few iron-clad rules of the comic, promised to the real woman upon whom Peejee is based.
- Something of a parody in Drawn Together: Captain Hero and Unusually Flexible Girl were Friends with Benefits in college and promised that if they were still single at 30, they'd get married. She shows up to collect.
- A variant in American Dad!: Stan asks his dentist to be his "back-up wife" in case he ends up outliving Francine. Hilarity Ensues when Francine finds out and decides to get herself a "back-up husband" for the same eventuality, in the form of Stan's attractive younger colleague. Unfortunately, it turns out both would-be spouses are taking it a lot more seriously than either of the Smiths expected...