Season 1
- In "The Witch", Xander asks Willow to kindly stop beating a dead horse: "Will, yeah, that is the point. You don't have to drive it through my head like a railroad spike." Much later, we find out that this was Spike's preferred method of torture, hence how he got his name.
- "I Robot, You Jane" ends with Buffy, Willow, and Xander bemoaning how hard it is to have a nice, normal, happy relationship on the Hellmouth. It's fairly lighthearted as none of the character's failed relationships to date were actually that traumatic, but considering all that happens over the next seven seasons it's really painful. It also seems like a Lampshade Hanging when, just after the characters have finished saying how hard it is to have a happy relationship, the episode closes out to Joss Whedon's Executive Producer credit, but given that Whedon wasn't really known for putting characters through hell just yet, it's probably unintentional.
- It wasn't known to the audience, but seeing as the executives had already shot down his plan to have Jesse's actor in the opening credits (later done with Tara instead) and he had planned to kill Joyce in Season One just to make Buffy's life harder, it's safe to say that the writing staff knew how cruel he was already.
- And that's not even considering the fact that this episode was Jenny Calendar's first appearance.
- In "Prophecy Girl", Buffy tells Angel he is never going to die. In the Season 2 finale, not only does Angel indeed die but he is killed by Buffy's hand.
Season 2
- In "Halloween", Spike is about to kill Buffy, who is weak due to taking on the personality of a colonial-era proper lady. The comment Spike makes about her and her situation before he makes the attempt sounds a lot like he's about to rape her. Keep this in mind when watching the infamous incident in "Seeing Red".
- In "The Dark Age", Jenny Calendar is possessed by a demon that jumps between dead or unconscious bodies. Willow realizes vampires, being dead, would attract the demon. Watch "Passion" and then go back and watch Giles fret "he's killing her" while Angel chokes Jenny into unconsciousness.
- Replace "demon who possesses dead bodies" with "evil entity that impersonates the deceased" and you have a the First Evil who makes its debut in season 3 and returns as the main villain of season 7. Bonus points for the demon possessing Jenny, whose form would be used in the First Evil's debut.
- In the Cold Open to "Bad Eggs", Joyce asks Buffy if she thinks of anything other than boys and clothes. Buffy responds that she thinks about saving the world from vampires. Then we get to season six, "Normal Again", where we learn that Buffy was once institutionalized for telling her parents about vampires. Joyce's exasperation in "Bad Eggs" takes on a much darker tone.
- Angel has mentioned several times that vampires can't have children. Now, go watch Season 3 of Angel.
- Similarly, in "Surprise", Drusilla freaks out over some flower decorations, mumbling that they're wrong, they're wrong, they're all wrong. Those flowers? Red roses. Given the events of "Passion", this is almost certainly not an accident.
- An in-universe example, the ending of "Lie To Me". Depressing and sad when aired, but the characters hadn't suffered great tragedy or major deaths yet. By the time the show is over that ending is second only to "The Body" in tear factor.
- On an out-of-universe basis, "I Only Have Eyes For You", which concerns an affair between a (young) teacher and a student that ends in a fatal shooting. Depictions of guns in schools have become quite unsettling after Columbine, and the Pædo Hunt of the past decade turns what was supposed to be a tragic love story into Squick for many people.
Season 3
- Way back in "Dead Man's Party", Buffy said to Xander, "Didn't anyone ever warn you about playing with pointy sticks? It's all fun and games until somebody loses an eye." In season seven, Caleb destroys Xander's left eye.
- The same for "Bad Girls", in which Xander covers his eye to keep Buffy from seeing his post-sex-with-Faith twitch.
- "Lovers Walk" where the viewers are made to believe Cordelia died. Compare that with the Angel episode "You're Welcome" where the viewers are made to believe Cordelia is alive.
- In "The Wish," Buffy suggests staking Anyanka. Giles says she's not a vampire, and Buffy says, "You'd be surprised how many things that'll kill." A few episodes later, Faith stakes the very human deputy mayor, killing him and leading to her Face–Heel Turn.
- Cordelia comments to Giles in "Gingerbread" that he was going to "wake up in a coma" on account of all the head traumas he had received. At the end of season 4 of Angel, Cordelia was left in a coma; she died without ever waking up.
- Faith screwing Xander's brains out in "The Zeppo" where he singlehandedly stops a plot to blow open the hellmouth? Funny and awesome. When it's revealed men are less than nothing to her? It stops being awesome. When Willow finds out and is in the bathroom crying? It stops being funny. And Faith later sexually assaulting then trying to kill Xander makes it this trope.
- Faith's never again mentioned sexual assault of Xander in "Consequences" got even more uncomfortable when Eliza Dushku revealed in 2018 that at age twelve, she was sexually abused by the stunt coordinator of True Lies, who even sabotaged a stunt and caused her to break a couple ribs as a threat of what would happen if she told anyone. This also casts the common fan assumption that Faith's mental issues might be related to childhood sex abuse in a darker light. And if that wasn't bad enough, Nicholas Brendon is himself a
survivor of childhood sexual abuse. - The Columbine High School massacre occurred one week before the original planned air-date of the season three episode "Earshot", which was about preventing a school shooting. It included this line by Xander:"Who hasn't idly thought about taking out the whole school with a semi-automatic?"
- After Buffy glares at him, he adds, "I said idly."
- Even The Stoic Oz would later have cringed over the comment about school shootings becoming trendy, since...well...they did.
- "Earshot" — whose plot involved a school sniper — was originally withheld from airing in the U.S. because of the Columbine shootings in April 1999. The season finale, "Graduation Day, Part 2" was also postponed the following month for similar reasons. Both episodes eventually aired later that summer, "Graduation Day, Part 2" in July and "Earshot" in September.
- Joss Whedons' ex-wife Kai Cole claiming that he confessed to committing adultery on the set of Buffy and other shows he ran with his excuse being he's a guy who found himself surrounded by beautiful women, leaving one to guess which actresses he was having sex with. That particular revelation also casts a very ugly light on Xander and Willow's season 3 "affair", particularly considering Xander (whom Whedon has admitted to be his Author Avatar) has a mostly No Sympathy response to Cordie's anger upon finding out.
Season 4
- In "The Freshman", Buffy is commenting on how her mother would react to the price of her text-books, stating flippantly, "I hope it's a funny aneurysm." Next season, her mother has a brain tumor removed, and later suddenly dies of a side-effect of surgery: an aneurysm. This quote was formerly the Trope Namer for "Funny Aneurysm" Moment before it was changed/merged into this trope.
- Some of the major events that most polarized fandom in Seasons 6 and 7, including Buffy and Spike hooking up in a relationship and Willow's witch powers spiraling out-of-control following her relationship ending, are (coincidentally or not) foreshadowed in Season 4's "Something Blue", to the point of the whole episode seeming Harsher in Hindsight. Heck, it even brought Amy back! (Albeit for only two seconds on-screen.)
- In the episode, Xander asks to be blind along with Giles after watching Spike and Buffy kiss. Again, this becomes less funny in season seven.
- Also, after Willow's spell-gone-awry is broken, Buffy jokingly tells her that "we may be into a forgetting spell later". This becomes less amusing in season six, where Willow's repeated use of magic to erase Tara's memories results in their temporary break up.
- In "Who Are You?", Buffy and Faith switch bodies, with the former appearing a complete and total Jerkass and the latter desperately trying to gain acceptance. Compare and contrast Season 7. Especially if one looks at the comics: Buffy's atoning for her past actions in Season 8 while Faith assumes the role as the more responsible Slayer.
- This line from Faith to Buffy in "Sanctuary" seems almost prescient of Buffy's arc in seasons 6 and 7.
Buffy: "I gave you every chance! I tried so hard to help you, and you spat on me. My life was just something for you to play with. Angel, Riley, anything that you could take from me, you took. I've lost battles before, but nobody else has ever made me a victim."Faith: "And you can't stand that. You're all about control. You have no idea what it's like on the other side! Where nothing's in control, nothing makes sense! There is just pain and hate and nothing you do means anything. You can't even.."- Also from "Sanctuary", Buffy in a moment of anger towards Angel tells that her relationship with Riley is better than the one she had with Angel because she trusts Riley. Season 5 has Riley betraying Buffy's trust by going to vampire brothels.
Season 5
- "The Replacement", in which Xander is split into two versions of himself. At one point he says to Anya that "very soon you won't be worrying about growing old!" Roughly three years later, in season seven, Anya is killed in the Final Battle.
- In "Family", when Tara asks Willow how she can make her feel the way she does, and Willow responds "Magic." In season six, Willow erases Tara's memory to make her feel love instead of anger towards her with magic.
- In "Triangle", Anya makes Xander promise that if he ever leaves her she wants lots and lots of warning, including "big flashing red lights and one of those clocks that counts down like a bomb in the movies and there's a whole bunch of coloured wires and I'm not sure which is the right one to cut but I guess the green one and then at the last second no, the red one, and then click, it stops, with three tenths of a second left, and then you don't leave." Next season, he leaves her at the altar with basically no foreshadowing.
- Buffy's melodramatic reaction to Xander and Anya's fight in this episode is played for laughs but her warning that small problems in a relationship can blow up into bigger ones proves to be sound as Xander and Anya break up in season 6.
- In "I Was Made To Love You", when the Scoobies discover that Warren built himself a robot girlfriend, it is Willow and Tara that show the most sympathy for him, that he couldn't find a nice, normal person to have a relationship with. At the end of the next season Warren kills Tara, and a heartbroken Willow murders him in revenge. The DVD Commentary by Jane Espenson suggests this foreshadowing was unintentional.
- Willow and Tara's fight in "Tough Love" has the former especially hurt and saying "I'm sorry I didn't establish my lesbo street cred" before they got together. This seems eerily prophetic of the years of fandom debates over Willow being gay or bisexual.
Season 6
- "All the Way", in which Xander dresses as a pirate. Xander's first line after he loses his eye mentions that pirate costume.
- The same episode has Anya nearly telling Dawn about a sex game, before Tara interrupts. And a similar situation in "Entropy", where Willow tries to cover Dawn's eyes as they see Anya and Spike about to have sex. Michelle Trachtenberg's mother later came out to speak about how disturbed she was about the inappropriate language used on set around her teenage daughter.
- For a few episodes late in the season, Xander is shown drowning his sorrows a bit too much and later mentions "hitting bottom." Two years later, Nicholas Brendon revealed that he's an alcoholic.
- The duet between Dawn and Sweet in "Once More With Feeling" has a light-hearted line where Dawn reminds him she's only fifteen and "this queen thing's illegal". Extremely awkward and Squicky in light of an incident that Michelle Trachtenberg has refused to elaborate on, where a private meeting between her and Joss Whedon led to a memo among the crew that he was never allowed to be alone with her again. note
- The mostly-lighthearted song "I'll Never Tell" between Anya and Xander from "Once More, With Feeling", in which they sing about their fears for the future, becomes Harsher in Hindsight twice over: Anya's line "I know that come the day I'll want to run and hide" after Xander leaves Anya at the altar nine episodes later, and Anya's fears about growing older when she dies in the Series Finale. The lyric "Will I get so old and wrinkly/That I look like David Brinkley?" led to another example on its British terrestrial broadcast, as The BBC aired the final episode the very week Brinkley himself passed away.
- In "Hell's Bells", Xander is shown a vision of himself in the future, in which he loses his temper and attacks Anya with a frying pan. In 2015, Nicholas Brendon was arrested for choking his girlfriend during an argument.
- The villain of the season - Warren Mears - is an adult nerd, who's a fan of comic books and sci-fi, and also has extremely misogynistic views towards women. The season was later noted to be ahead of its time in its highlighting of the misogyny that can show up in 'nerd spaces', but as time has gone by and allegations against Joss Whedon piled up, Warren starts to look like a somewhat uncanny resemblance of the man himself. Case in point - "Dead Things", where Warren makes his ex-girlfriend dress up in a skimpy costume and serve him and his friends isn't too dissimilar from Joss Whedon's show Dollhouse, which is about a protagonist (played by Eliza Dushku) whose mind is wiped and is often forced into sexual encounters.
Season 7
- In "Same Time, Same Place", Buffy kills a flesh-eating demon named Gnarl by poking his eyes out with her thumbs, a sight that Xander responds to with understandable and amusing disgust. (His exact words are "Eww, thumbs?") Several episodes later, psychotic preacher Caleb drives his thumb into Xander's left eye. Earlier in the same episode (overlapping with Foreshadowing), when describing the critical targets on a potentially unknown enemy:Xander: Go for the eyes. Everything has eyes.
Xander: I'm the guy who sees everything
Caleb: So I hear you're the guy who sees everything. Let's fix that - Anya in "Selfless" tells Buffy that it will take more than a sword through the chest to kill her. She is killed in the finale by a sword through the chest. Though, to be fair, swords didn't do as much permanent damage when she was a vengeance demon.
- An in-universe example and lampshading occurs in "Conversations With Dead People":
- Holden: Hey, you remember Jason Wheeler, you know, "Crazy J"?
Buffy: Oh, yeah.
Holden: He always had that shtick of [waves hands around] "Yeah, I'm crazy, I'm crazy!"
Buffy: How is he?
Holden: Crazy. He's been in the chronic ward since graduation. (Beat) Not really that funny, I guess.
Other
- Xander's animosity towards Angel become this considering that, if Emma Caulfield is to be believed, Brendon "wasn't a fan" of David Boreanaz. It got to the point where Boreanez had Brendon blocked from the twentieth anniversary photoshoot (possibly due to his alcoholism).
- Speaking of vampires that Xander doesn't like, the undignified treatment Spike suffers from Buffy season 4 onwards takes on a whole new meaning in light of James Marsters' account of being on the receiving end of hostile and unprofessional behavior from Joss Whedon, who apparently wasn't happy about Marsters' character being too popular to be killed off as he intended. Considering Xander is also Whedon's Author Avatar, the fact he is the most distrusting and hostile of the Scoobies towards Spike has some uncomfortable subtext.
- Charisma Carpenter's accusations of abuse against Joss Whedon which were confirmed and backed up by several castmates throw the entire show into this, particularly Cordelia's treatment and the overall "feminism" of the show. Even moments that were still empowering now feel insincere knowing that behind the scenes, they were dealing with intense toxic behaviour. These accusations also shine a rather ugly light on several stories James Marsters has been telling for years about Whedon's treatment of him on-set over Spike's unexpected popularity—including but not limited to the time he'd been pinned to a wall and told he was "dead". What had once just seemed like mostly harmless anecdotes now seems like a peek into long-standing workplace abuse.
- Carpenter's account also makes a scene in "Belonging" (episode 19 of Angel season 2) where a director is rude towards Cordelia seem even more uncomfortable.
- A meta case; there was a story heartwarmingly enjoyed by the fandom where Michelle Trachtenberg was a huge fan of Buffy and apparently got cast in the show when she told Joss Whedon "there was never a Buffy episode that sucked, I love you!" - which becomes extremely sad in light of Michelle alleging that he later behaved very inappropriately towards her.
- After breaking up with Xander, Anya is apart from the gang, and the latter parts of Season 6 and early Season 7 emphasise how lonely she now is. Emma Caulfield later said that she felt "very underappreciated" on set.
- The speech to Cordelia about wanting to live in the world for a moment, in spite of her duty, at the time? Sad. Given everything Cordelia goes through over the course of Angel for her duty? Oh dear God.
