As Leonard is reading the sixth "Harry Potter" book, Sheldon spoils it for him by telling him that Dumbledore dies. Leonard comments that if he had told Sheldon about the huge spoiler, Sheldon would have complained about it for weeks. Sheldon asks if Leonard is going to have a hissy fit, which he attributes to the estrogen levels in the soy milk that he drinks due to his Lactose intolerance. Leonard retorts that Sheldon is annoying, controlling and that he dislikes his current living situation. Blithely, Sheldon interrupts Leonard. In return, Leonard then repeats that Sheldon is the most annoying person he knows. Leonard walks away, declaring not to endure any more, while Sheldon quotes the Roommate Agreement. Leonard disposes of the Agreement contract. Nonetheless, Sheldon cites section 25, paragraph 5 and that, like the American flag, it cannot touch the ground. As Leonard leaves the apartment, Sheldon tells him that Dobby the Elf dies in the seventh Harry Potter book.
At Howard and Bernadette's apartment, Raj delivers Howard's suitcase that he had borrowed two years ago. The Wolowitzes are off to a conference in Las Vegas with some of Bernadette's colleagues as a bonus. Bernadette gives the reason for this trip: a new dandruff shampoo had that caused anal leakage is to be relabeled as a cure for constipation, saving the company money. Howard asks Raj to look in on his mother because she has been depressed since her dentist boyfriend dumped her. First, Raj complains that he is single and that Saturday is his party night. Howard scoffs at him and Raj agrees to the errand.
While at Penny's apartment, Penny listens to Leonard's claims that Sheldon is the most egotistical and insufferable person he has met. Penny quips that they make a cute couple like Bert and Ernie from "Sesame Street". They even teach her about words and numbers. Leonard then announces that he can't live with him for another minute, and that he wants to move in with Penny. Penny is nervous, and an oblivious Leonard goes to make plans to move in.
Raj is finishing dinner with Mrs. Wolowitz and she asks him if he wants any dessert. Raj declines. She then declares that she is lonely and has nothing to live for. Raj tells her that he can stay for dessert, to which she replies that she will make him a chocolate cheesecake.
Sheldon is loading a box of Leonard's collectibles with Amy when she proposes that she move in with Sheldon, using her knowledge of his quirks and foibles to polish her chances; she concludes that she is ideal, and makes plans to move in, much like Leonard has done with Penny. Terrified, Sheldon appeals to Leonard and Penny, imploring for Leonard to return and that changes will be made to the Roommate Agreement. While Penny concedes with Sheldon's concerns due to her feelings, Leonard is unfazed by Sheldon's entreaties and ignores him.
Howard checks on Raj and finds Raj in Howard's old bed wearing his silk pajamas. Mrs. Wolowitz calls him for breakfast, while Howard warns him that his mother will imprison him. Raj is doubtful until he discovers that his clothes have been hidden.
Sheldon confronts Penny; Penny is unaware of her misdeed. Sheldon replies that the situation is untenable because of her and Leonard. Penny concurs with him, and that the truth is that she is hesitant to have Leonard living with her, but does not want to break his heart because she loves him. The two finally conclude that each of them is going to have to tell their significant other the truth.
In Las Vegas, Howard and Bernadette are putting on ice packs due to a misbegotten sexual stunt, when Raj sends Howard an urgent video chat for help. Howard tells him that he wanted a woman in his life and now he has one. Bernadette asks if they should go and rescue him and Howard replies that they will just have to see him at his Bar Mitzvah.
In apartment 4A, Amy is serving Chinese food exactly how Sheldon likes it. Sheldon asks Amy whether them living together will take the mystery out of their relationship; Amy denies it. She then shows him a script for their phone answering machine message. Sheldon says that the situation cannot happen. Stricken, Amy angrily inquires why she cannot live with him. Sheldon pins this problem on Penny, since she doesn't want Leonard to live with her. Amy runs over to Penny's to confront her. As the standoff takes place, Penny explains to Leonard that she is not ready to live with him. Amy is upset with Sheldon's deception, and she and Penny retire to Penny's apartment, leaving Leonard and Sheldon to return to their own apartment and watch some of The Walking Dead. Sheldon lets a spoiler slip, though he hastily assures Leonard that it is ambiguous.
In the final tag, Raj is seen still trapped in Mrs. Wolowitz's house and unsuccessfully tries to escape.
- Guest starring:
- Teleplay: Steven Molaro, Maria Ferrari & Adam Faberman
- Story: Chuck Lorre, Eric Kaplan & Steve Holland
- Oliver Sava of The A.V. Club gave the episode a A++.
- Jesse Schedeen of IGN gave the episode a "Great" rating of 8.5/10.
- Dhruv Rao of The DR Club gave the episode a A++.
- IMDb user reviews
- Title Reference: The title comes from a comment made by Leonard just before he slams Penny's door in Sheldon's face. Penny also quips to Leonard, "Spoiler alert!"
- Chuck Lorre's vanity card.
- This episode was watched by 22.94 million people with a rating of 8.0 (adults 18-49).
- Total viewers including DVR users 22.94 million.
- This episode aired in Canada on February 7. 2013 with 3.561 million viewers and a weekly ranking of #1.
- In the United Kingdom, this episode aired on May 9, 2013 with 3.561 million total viewers.
- Episode transcript 
- Second time a glimpse of Howard's mother is seen. The first was an overhead shot of her in a pink outfit in "The Countdown Reflection" (S5E24). Here, one can observe she has long, dark hair. but her face was never ever shown; however, her arms were seen when she grabbed Raj from the window at the end of the episode.
- Second episode where characters go to Las Vegas; the first was "The Vegas Renormalization".
- Bernadette only appears in one scene of this episode (The scene at the Las Vegas motel where she is in bed with Howard wearing a sexy red nighty and with her glasses off, as some people do not wear glasses in bed anyway, meaning that she doesn't wear her glasses in this episode at all).
- Bernadette does not appear with Howard and Raj at their apartment with her glasses on and with her ordinary day clothes on in the Howard in the packing up for Vegas scene (with Raj sitting on the settee next to him) of this episode. She might be at work that day. There is no background appearance or speaking role by her in that same Howard and Bernadette's Apartment scene of this episode either.
- Howard and Bernadette are not seen at the dinner table with Raj at Howard's mom's place. They are already at Vegas hence why they did not come to Mrs. Debbie Wolowitz's house to eat dinner with Raj before their journey to Vegas.
- The story line does not show Bernadette at work asking which ones of her colleagues would like to come on this course to Vegas with her and her husband Howard.
- There is no appearance by one or two of Bernadette's colleagues (as they are just mentioned by Howard) and there are also no other room background appearances by other parts of Vegas until Penny's Posse's vacation to Vegas in "The Focus Attenuation" (S8E5).
- There are no other scenes with on-screen appearances by Bernadette with her glasses on and with her ordinary day clothes on in this episode until the next episode (S6E16).
- Both Sheldon and Penny tell Leonard what happens in the Harry Potter books that he hasn't yet read. It is unknown why Leonard, an avid fan of the fantasy arts, has never read or watched any of the books or films of one of the biggest franchises in the history of the fantasy genre, or even stumbles. upon any of the details from one of his friends up until now. This is despite them watching the first film in series four.
- Penny admits she loves Leonard for the first time without doing it accidentally.
- Amy claims the Relationship Agreement is ridiculous even though she found it quite romantic when Sheldon first showed it to her in "The Flaming Spittoon Acquisition".
- Amy knows how Sheldon thinks and presents him with an ironclad argument on why she should move in and why she would be his perfect roommate.
- Penny denies that Leonard asked whether she was ready for them to move in together, though Leonard did ask her if there was any reason that they shouldn't. Penny didn't want to hurt his his feelings and there was no logical reason.
- Penny likens Sheldon and Leonard's relationship to Sesame Street, and then calls Leonard Bert and Ernie|Ernie when she was trying to get him back together with Sheldon. Previously in "The Creepy Candy Coating Corollary" (S3E5) she mentioned that as a little girl she wanted to marry Ernie. This coincidence may be a subtle hint as to her intentions toward Leonard.
- Amy never looks happier or smiled as much than when sitting in "their" apartment with Sheldon and discussing moving in with her boyfriend.
- The story line doesn't show how Raj managed to get out of Howard's mother's house. The likely scenario is that Raj was stuck there until Howard and Bernadette returned from Vegas.
- A spoiler alert warns someone of an element of a disseminated summary or description of any piece of fiction that reveals any plot elements which threaten to give away important details concerning the turn of events of a dramatic episode.
- Though the term "spoiler alert" has been used before, this is the first episode and episode title based on that term.
- Bernadette shares no scenes with Sheldon, Penny, Leonard and Amy in this episode and she has no physical appearances with Raj in this any scenes of this episode either.
- At the end of the episode, Sheldon mentions watching AMC's "The Walking Dead" with Leonard. It's interesting to note that in "The Staircase Implementation" (S3E22) Steven Yeun appeared as a guest star, portraying Sheldon's former roommate. Yeun also portrays Glenn Rhee, a main character in "The Walking Dead."
- Even though Sheldon never tells Amy why he doesn't want to live with her, there are several reasons he could justify this:
- She is old fashioned and religious.
- Sheldon fears that his mother would not approve of them living together out of wedlock.
- If they have an argument Sheldon would have to sleep on the couch and if they break up one of them may have to leave the apartment.
- Leonard: I swear, that man is the most egotistical, insufferable human being I have ever met.
- Penny: Yeah, but you two make such a cute couple. Like Bert and Ernie. You guys even teach me stuff about words and numbers.
- Leonard: Well, I’ve had it. I am done. I can’t, I can’t live with him for one more minute.
- Penny: Wow. Where are you going to go?
- Leonard: I was thinking here with you.
- Penny: Oh.
- Leonard: That a problem?
- Penny: No, not at all. No, it’s, it’s great. It’s terrific. I, you know, I just can’t help feel bad about Sheldon. I mean, how’s he going to get by without you? Ernie.
- Amy: So, what’s your plan moving forward?
- Sheldon: I suppose I’ll have to find and cultivate a new roommate. What a task that will be. Do you know how uncivilized Leonard was when I took him in?
- Amy: No.
- Sheldon: It took me forever to get him on a bathroom schedule. He would go whenever the mood struck him.
- Amy: Like a dog boy.
- Sheldon: Exactly.
- Amy: What if you could find a roommate who was a scientist and already familiar and comfortable with your ways?
- Sheldon: That would be ideal. If a person like that existed I would sign on no further questions asked.
- Amy: Great! Here I am!
- Sheldon: Wait. Here who is where?
- Amy: Me. Aren’t I your perfect roommate?
- Sheldon: Um.
- Amy: Think about it, Sheldon. I’m not a stranger. We’re intellectually compatible. I’m willing to chauffeur you around town. And your personality quirks which others find abhorrent or rave inducing I find cute as a button. What do you think?
- Sheldon: Um.
- Amy: Tell me one reason that this isn't a fantastic idea.
- Sheldon: Um.
- Amy: See, you can’t. I’m going to see if Leonard’s room is big enough for my water bed.
- Sheldon: Um.
- Sheldon: You can’t live here.
- Amy: What? Why? Is it the answering machine message? I only used urban slang to sound tough so people wouldn't break in.
- Sheldon: It’s not the message.
- Amy: What is it then? I did everything just the way you like it.
- Sheldon: You did.
- Amy: THEN WHAT THE HELL, SHELDON!?!? We have been going out for over two years and I have been nothing, but patient with you. I watch your dopey space movies. I signed your ridiculous contract. I even stopped wearing lip gloss because you said it made my mouth look too slippery. I am the best girlfriend you’re ever going to have. Just give me one good reason why I can’t live here.
- Sheldon: It’s Penny’s fault.
- Amy: What?
- Sheldon: She doesn't want to live with Leonard so he has to live here again. She’s the snake in our garden. She’s the reason we can’t be happy.
- Penny: Hey, Ames.
- Amy: Yeah. Hey, Ames, nothing. I was all set to move in with Sheldon, and now I hear I can’t ’cause you don’t want to live with Leonard.
- Leonard: (off) What?
- Penny: Sheldon, what did you say?
- Sheldon: I said the truth. You don’t want to live with Leonard, and you know it.
- Leonard: Since when don’t you want to live with me?
- Penny: Oh, don’t get all huffy. You’re the one who decided to move in without even asking me if I was ready.
- Sheldon: Yeah, I think we should talk about that.
- Penny: And since you love the truth so much, why don’t you tell Amy you don’t want to live with her instead of blaming it on me?
- Sheldon: I thought we were talking about the other thing.
- Amy: You’re a coward.
- Sheldon: Well, the evidence does support that.
- Penny: Come on, Amy, let’s go drink wine and talk about what jerks our boyfriends are.
- Amy: You know what would show them? I should move in here with you.
- Penny: Um…
- Leonard: You know what? Screw you, Sheldon. You are the most annoying person I have ever met.
- Sheldon: What? I’m annoying? You criticize my behavior all the time. "Sheldon, don’t talk about your bowel movements over breakfast". "Sheldon, when the president of the university is giving a eulogy at a funeral don’t yawn and point at your watch". "Sheldon, don’t throw away my shirts ’cause you think they’re ugly". You’re impossible.
- Leonard: That’s it. I don’t, I don’t have to put up with this.
- Sheldon: Actually, I have your signature on a roommate agreement that says you do.
- Leonard: Aw. Here’s what I think of your roommate agreement. (Throws the roommate agreement in the garbage can)
- Sheldon: (gasps) You pick that up right now.
- Leonard: No.
- Sheldon: Roommate agreement, section 27, paragraph 5, the roommate agreement, like the American flag, cannot touch the ground.
- Leonard: I don’t care. I don’t have to do anything you say because I don’t think I want to live here anymore.
- Sheldon: Where are you going?
- Leonard: To live with Penny and not you, you crazy bastard.
- Sheldon: Crazy bastard?
- Leonard: Yes.
- Taping Report by Kyzzx
- The Big Bang Theory - The Spoiler Alert Segmentation (TV Episode 2013) - IMDb
- The Big Bang Theory: “The Spoiler Alert Segmentation” - TV Club - The A.V. Club
- The Big Bang Theory: "The Spoiler Alert Segmentation" Review - IGN
- The Spoiler Alert Segmentation/S6E15 - The DR Club
- Live+7 DVR Ratings: 'Modern Family' Leads Adults 18–49 Ratings & Total Viewership Gains; 'Revenge' Earns Biggest Percentage Increase in Week 20 - Zap2it
- Top Programs – Total Canada (English) February 4, 2013 – February 10, 2013 - BBM Canada
- BARB via Wikipedia