Shaman King: On the off chance that Yoh gets killed in the Shaman tournament, Anna asks him to have sex with her the night before his next fight. More exactly, she asks if they can sleep in the same room that night, but the intention behind that is very obvious even if not 100% spelled out.In one of his rare serious moments, Yoh agrees. And as a result, Anna gets pregnant with their son Hana.
In the first volume of Crying Freeman, Emu Hino wants to experience her first time with Yoh Hinomura before he dispatches her, and straightforwardly asks him to be her first. Luckily, Yoh (who also is a virgin) finds this cake too good to throw out, and takes her in instead.
Mirai Nikki: Yuki and Yuno, who are both virgins before Chapter 52.
Thoroughly deconstructed in the Bokurano manga, where Isao Kaku, upon learning of his impending death via Humongous Mecha piloting, tries to lose his virginity by attempting to rape his crush and fellow pilot, Chizuru "Chizu" Honda. Not only Chizuru was a rape victim who was pregnant due to it, but she first repels Kako's forceful attentions, then later ends up killing him.
Yokoshima in Ghost Sweeper Mikami constantly try to hug/kiss a nearby female whenever the situation turns bad, saying things to the effect of this.
In 3×3 Eyes, Yakumo and Parvati have sex before she leaves for the humanization ritual.
Subverted in Fushigi Yuugi. Miaka and Tamahome decide that (just in case one of them dies in the ensuing battle with Nakago), they will consummate their relationship. However, Miaka's stomach grumbles, which ruins the mood. That, and the fact that Miaka has Virgin Power.
When Italy first meets Germany in Axis Powers Hetalia, he pleads for his life, telling him he's still a virgin.
"Oh, no! I don't want to die a virgin!" "You're a virgin?" "Look, do you want to get some or not?"
Kitty Pryde tried to fufill this trope with Colossus in Unncanny "X-Men" #165 when it seemed like both were doomed to die from Brood infection. However, Colossus refuses because of her young age, despite her pleas.
Amazingly, Mystique seduced Iceman by persuading him to pretend that he was going to die the next day; in his case this was almost true as she was wearing poisonous lipstick supplied by Mister Sinister; fortunately, Bobby didn't die and it was the start of a brief, though torrid, relationship.
In Teen Titans Annual #1, during "Infinite Crisis", Wonder Girl volunteers to look after Superboy as he recovers while the other Titans are called away to organize the relief effort in a decimated Blüdhaven, since her powers are slowly vanishing. Superboy awakens, and he and Wonder Girl spend time alone, reminiscing and longing for "simpler times". Thinking this may be their last night together, the two consummate their relationship in the Kent barn.
The Punisher: there's an in-universe book called "Valley Forge, Valley Forge" written by the brother of a soldier who served with Frank in Vietnam. At one point, the author states that he was reasonably certain that his brother lost his virginity before he left for Vietnam. He would eventually die in battle.
Played with in ElfQuest: The Rebels. When Chandra is convinced the city they are in is doomed and there is no way they can survive, she propositions Scorch. He doesn't really get it, because runs off before she's finished talking, because her phrasing gives him an idea how to save the city.
During this chapter of the Code Geass fanfic In the End, Lelouch has sex with C.C before he banishes her.
One of the most popular tropes in Code Geass fanfiction is Lelouch having sex with Suzaku or CC....or both the night before Zero Requiem.
Played with in Relax, where the protagonist is not a virgin, though he's still seeing the same prostitute who took his virginity. It's more a case of I don't want to die before I see you again.
In The Second Try, Shinji and Asuka spend together in NERV's locker room the night before their final battle against the JSSDF and SEELE's MP-EVAs. Since this story is a Peggy Sue, it's actually their second first time.
Films — Live Action
Alicia Casse's boyfriend from Independence Day tries to talk her into losing her virginity, seeing as the world is probably going to be destroyed by aliens. Foiled by Alicia's Big Damn Brother interrupting and taking her home. Given a slightly touching revisit in a deleted scene, where Alicia says the same thing to a boy in the underground bunker, and he replies that if they don't make it, they'll both die virgins, but at least they'll die together.
Played for laughs in Zombie Strippers. A chaste young man and his equally virginal girlfriend are trapped in a room while zombies pound on the door outside. As it seems their deaths are imminent, he suggests they have sex. After she shoots him down, he begins to run off a list of increasingly filthy sex acts that they could perform instead. When she asks where he's even heard of this stuff, he replies "The Internet".
Grease 2: Intentionally invoked and set to music, with the song "Let's Do It For Our Country". One of the guys brings his girlfriend down to the bomb shelter, where a confederate sounds the bomb siren to make her think it's The End of the World as We Know It. Cue musical number. Unfortunately, she misses the point and thinks he's singing about joining the army, and when the siren stops, she rushes out of the shelter only to find his buddies listening at the door.
In one of the many dramatic scenes in The Sinking Of Japan, the protagonist's girlfriend aks him to make love to her before they both die. The protagonist politely declines, saying that they will have their chance when they meet again in London. The protagonist is really going to perform a Heroic Sacrifice and wants to save his girl the sadness.
A variation in the After the End movie Testament, played as a pure Tear Jerker: A girl dying of radiation poisoning asks her mother to describe what it's like to make love, since she knows she won't live long enough to find out for herself.
In a very brief scene in Evolution, after the potential end of the world is released to the public, there's a large scale college party/protest for The End. One girl is holding up a sign which says "I Don't Want To Die A Virgin".
A subversion in joke form: The captain of a cruise ship announces the ship is sinking, and there aren't enough lifeboats for everybody. One young woman stands up and starts yelling that she doesn't want to die without knowing what it's like to be a woman. Then a Tall, Dark and Handsome man stands up as well, slowly approaches her. With everybody watching, the young girl trembling with anticipation, he rips off his shirt and throws it in her face, yelling "Here, iron this!"
In Battle Royale, Niida tries to persuade Chigusa of this. Unfortunately, he doesn't take "no" for an answer and becomes a bit more forceful...
In Squire, before Kel is set up to joust against Lord Wyldon, Cleon jokingly makes this offer to her. She calls his bluff, but realizes that the only reason he does not want to sleep with her is that he wants to marry her in proper Noble fashion—with her as a virgin. He's trying to talk his mother around to allowing them a marriage, and wants to prove that he doesn't just think of Kel as a happy fling.
Happens in Good Omens when Newt and Anathema were caught in the big pre-Apocalypse storm. Made funnier because it was prophetized by Anathema's ancestor, Agnes Nutter, and subsequent family members had added encouraging comments and cat-calls on an index card with the prophecy. Even better, said prophecy refers to something else entirely. Agnes must have deliberately wrote it that way to play matchmaker.
In A Darkness at Sethanon, squires Jimmy and Locklear hook up with two girls about their age before the sack of Armengar. Both of the girls and the street-smart Jimmy are extremely casual about it, while the naive Locklear overreacts and decides he's going to marry the girl he slept with, who inevitably dies. This is in contrast to their roles in later books, where Locklear is a suave ladies' man and Jimmy is Happily Married.
In Michelle Magorian's A Little Love Song/Not a Swan, set in 1943, Derry convinces Rose to have sex with him before he goes to war, invoking this trope. It isn't until after he has left town that Rose finds out that Derry wasn't even allowed to join the army, and tricked her into having sex with him to boost his own ego.
Adrian Mole, in his first diary, commented that he hoped the bomb wouldn't be dropped before he finished his O Levels as he didn't want to die an unqualified virgin (and getting laid seemed unlikely).
In the first book of the Tales of the Otori series, Iida Sadamu uses this as justification for attempting to rape Kaede when she resolved that she would have to commit suicide. He doesn't get far.
In Gust Front, it's Lampshaded, then carried out a few chapters later, with Tom Sunday Jr and Wendy Cummmings (the latter being the virgin, in this case, and not the geeky former) during the Fredericksburg engagement, after the building-sized FAE bomb is detonated and they're waiting for recovery.
In Clockwork Princess, Will and Tessa have sex when they are trapped together in a prison cell and believe the Magister is in all likelihood going to kill or enslave them the next day.
Live Action TV
Buffy: Parodied in Xander's dream in "Dirty Girls":
Girl 1: I've never been with a man. I could die tomorrow, and I've never been with a man. Xander: Well, uh? Girl 2: I've never been with a man before either. Xander: Colleen. Girl 2: I've never been with herin front of a man before. Girl 1: I've never been with her in front of a man, either. Xander: Um... Girl 1: Xander... Girl 2: We're so scared. Rona: Xander! Xander! Goddamnit! Xander:(wakes up) What's going on? I was sleeping. Rona:Dominique has the stomach flu, and the toilet bowl is backed up.
Not played for laughs on Buffy's 17th birthday. She and Angel barely survive an encounter with an apocalyptic demon, so decide to consummate their love, destroying Angel's soul and creating the realBig Bad.
"You've never had anything that's real... [...] and if this is the end, I want you to have something that is."
Supernatural: Just before an encounter with an archangel that the characters believe will prove fatal, Dean, on hearing that Castiel "never had occasion" to lose his virginity, attempts to set him up with a hooker (called Chastity, no less). Hilarity Ensues.
Dean: What did you do!? Castiel: Nothing. I just looked deep into her eyes and told her that her father, Stan, didn't leave because he didn't love her. He just hated his job at the post office.
In the Australian mini-series 1915, the two couples consummate their relationships before the boys ship off to World War One. One of the girls becomes pregnant.
Scott and Chloe on Stargate Universe, after learning that Destiny is about to fly into a star. They both survive (much to their surprise), and it becomes their relationship upgrade.
No Ordinary Family: Referenced for laughs in the first episode; on a plane experiencing engine failures during a storm, the teenage daughter of the family wails that she's going to die, "and I haven't even done it yet!" With both her parents in earshot. They look... unsure how to respond to or feel about this.
The remake of the TV Movie The Initiation of Sarah does this, but interestingly it's actually tied to the plot. Right before the Good Sorority goes to try and stop the Evil Sorority, Sarah goes to *ahem* "be with" her boyfriend. However, it was earlier established that the Evil Sorority were a group of witches who were sacrificing virgins to prep for a ceremony, so Sarah was trying to take her boyfriend off the menu.
The Mash episode "The Army-Navy Game" has the 4077th threatened by heavy shelling and an unexploded bomb in the compound. Radar, of all people, manages to cajole a nurse into joining him in the supply tent.
One episode of Scrubs has Elliot and Carla attempting to find a male prostitute for a dying patient with this attitude. They end up getting arrested, while the patient does the deed with Ted.
In Andrew Marvell's poem, "To His Coy Mistress," he basically tells the woman in verse that life's too short to be shy, and that if she dies a virgin "then worms shall try/ That long preserv'd virginity."
The Bible: In the book of Judges, Jephthah must give his daughter over to the Tabernacle as the result of a promise to God Gone Horribly Wrong, meaning that she will never marry (a variant reading argues that Jephthah sacrificed his daughter the old-fashioned way, i.e. on a pyre). As a compromise, he allows his daughter two months to go up and down the mountains bewailing her virginity.
In Mass Effect 1 and 2, the protagonist and his/her Designated Love Interest have a chance to consummate their relation before the game's final mission. Most of the options definitely aren't or probably aren't virgins, the exceptions being Tali and Liara. Tali because her race's unique answer to the immune system leaves a very high chance that she'd be allergic to any potential partners, even of her own species, while Liara explicitly mentions that she's never been in a romantic relationship.
In Dragon Age: Origins, if the female Warden is romancing Alistair (who reveals himself to be a virgin after getting to a "good friends" sort of stage) and doesn't proposition him herself, once it's been going on for a while, he'll eventually approach her, saying that seeing as they face danger day-to-day, he wants to take advantage of having the chance and "say I threw caution to the wind just this once".
In Saints Row IV, The Boss can offer to have sex with Matt Miller so that he doesn't die a virgin.
One of the non-canon endings to Red vs. Blue has Tucker try this on Sister, who's more than eager to get to it. Until Grif kills Tucker. Tucker tells Grif in Revelations that "I fucked your sister." Normally, one would take this as an empty taunt, but this is Sister we're talking about...
Lord Grater: You said you'd give me a kiss if I was the last man in the universe, and I am! Princess-Princess:I said I wouldn't kiss you even if you were the last man in the universe!!! Lord Grater: Oh. Never mind.
In Tripping the Rift, expecting they are about to die, Whip asks Six to take his virginity as he does not wish to die as a virgin. She agrees, but just before anything can happen, they are saved, much to his dismay.
Whip: Why couldn't we have been saved ten minutes later?
Six: You would have only needed ten seconds.
Downplayed in Family Guy (ironically the last show you'd ever expect a sex trope to be downplayed in) when Meg and Neil are about to be killed by a serial killer, Meg exclaims that she has never even had her first kiss, Neil claims that there is still time.
In King of the Hill episode Texas City Twister, Nancy, while reporting on the tornado, suggests that the people at the trailer park that if one hasn't experienced the miracle of love making, that now would be a good time.
Subverted in Bob's Burgers episode "Food Truckin'", when the family is trapped in their overturned Food Truck and Tina declares that she doesn't want to die a virgin, to which trapped with them Randy response to with "Me too", causing Tina to perk up saying "That gives me an idea!", which Bob quickly responds to with a harsh no.