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"The Separation Oscillation" is the second episode of the ninth season of the American sitcom The Big Bang Theory. The episode aired on Monday, September 28, 2015.


Leonard meets with Mandy Chow to talk in an attempt to fix his marriage to Penny. Meanwhile, Sheldon recorded an episode of "Fun with Flags" about his breakup with Amy. And Bernadette feels guilty about keeping the Mandy Chow secret from Penny.

Extended Plot[]

Leonard cannot sleep and is up in the kitchen of 4A. Sheldon comes in and also cannot sleep because of a tickle in his throat. Penny joins them. Leonard asks Penny how he can make everything right. Sheldon interrupts and suggests Penny kiss another man to make everything equal. Leonard objects to that idea, saying that's the stupidest idea he's ever heard, but Penny agrees with Sheldon. Leonard asks Sheldon what was going on. Sheldon says he is saving his best friend's marriage and plants a big kiss right on her. Penny responds by jumping into his arms and wrapping her legs around him. Leonard then wakes up and realizes everything that just happened was all a crazy nightmare.

Screen Shot 2015-09-29 at 3

Shenny kiss! Leonard's nightmare.

Sheldon calls up Amy on Skype, who gets upset that he doesn't realize what a breakup is. Every time he talks to her, she gets re-traumatized. Amy wants to know what he wants. Sheldon admits that they are no longer together, but there is the baby that they made, the Internet show "Fun with Flags". He wants her to come over and help him with the next episode; however, Amy is not going to help him. Sheldon tells her that Sonny and Cher made their show work after their divorce. Amy complains that she has talked to him more in the last two days than in the last two months of their relationship. Sheldon quips that if she doesn't want to talk to him, maybe she should go out with him again.


Raj feels left out of Howard's life.

 At the comic book store, Raj tells Leonard that he can't believe Leonard made out with Mandy Chow and that Howard didn't tell him for two years. Raj starts arguing with him like his spouse. Leonard wonders why his problem affects the two of them. Howard tells him to try having two wives.

Sheldon arrives at Amy's apartment with a box of her personal belongings for him to return. He knocks only once so that Amy doesn't know it's him. Amy mentions the single knock; while Sheldon tells her that she doesn't get to enjoy anymore of his charming eccentricities. They are not "friends with benefits". Out of the box Amy takes out a scarf of hers and is surprised Sheldon still had it. It was from the time they went ice-skating together. Next Amy pulls out a sexy red bra which isn't hers, but is planted by Sheldon in an attempt to make her jealous. Amy remarks that this doesn't belong to her to which Sheldon explains: 'I don't remember who it belongs to either as I have been with so many different women lately' Amy gets mad, grabs the box and slams the door on him. Sheldon then knocks on the table in the hall to finish his knocking ritual.


Leonard is the bad guy.

Bernadette is making Chocolate brownies for Girls' Night and is mad at Howard, but not for what he bought. Howard told her about the Mandy Chow incident and is mad at Howard that she had to keep the secret from Penny for two years. She's terrified about what Penny might do if she finds out Bernadette knew but didn't say anything. Howard counters this by claiming Leonard is the bad guy for telling him.

Leonard is on the phone trying to find a marriage counselor. After he learns how expensive they are, he wonders if they have a rate based upon how long one had been married like a day. Penny interrupts him and they sit down to talk.


This belongs to you.

She doesn't know how to fix them. Sheldon comes in and returns Penny's bra to her prompting her to request an explanation, but after she is finished talking with Leonard. Returning to the topic, Penny knows that she said that she could get by it, she doesn't know what to do since he is going to see Mandy Chow tomorrow at work. Sheldon suggests a simple solution, scaring Leonard because it's the same way that his nightmare started. Sheldon suggests that Penny go to meet Mandy Chow to alleviate her fears since her imagination is running wild. Leonard thinks that that is a terrible idea and Penny does not want to meet her though she is still worried that Mandy Chow might still have interest in him.

Girls Night

Leonard used to be less cocky.

The girls are together in Penny's apartment discussing the recent events. Penny points out that Leonard would have never done this when they first met. He's cockier now. Amy points out that Penny made him that way. Bernadette points out that it is better for them both if he is with her because he wants to be rather than because she is his only option. Penny says she had never thought of it that way. Bernadette, still feeling guilty, says sure, that she had just thought of it.

At the Caltech cafeteria, the guys are having lunch and Leonard asks them if they know how much a marriage counselor gets. Howard knows. Raj again asks why he doesn't know. Mandy Chow walks into the cafeteria. Leonard goes over to see if she would

Did I Sleep With You Too

Did I sleep with you too?

be willing to talk to Penny. He greets her, sits down and asks about what they did on the boat while they were drunk. She asks if she slept with him too. No, they just made out. She remarks "Good for me." Leonard tells her that he just got married and she asks to Sheldon, which she's implied to have asked him a number of times. Leonard tells Mandy Chow about Penny's concerns and she wonders why he even told her since it was just a kiss. Leonard was making sure there were no secrets between them. To Mandy Chow it sounded more like he was sabotaging their relationship just like Penny had said. Mandy Chow has unwittingly become the marriage counselor that he needs. He then starts to open up to Mandy Chow that he didn't think that he deserved a beautiful woman like Penny. He then gets into his dysfunctional relationships with his mother and Sheldon, even more disturbing Mandy Chow. Finally, he had this dream where he was in a cave Nursing|nursing a baby Sheldon. Now Mandy Chow wonders why Penny is worried about HER.

My Right Hand

Sheldon solo on Fun with Flags.

Amy is watching the "Fun with Flags" episode where Sheldon angrily compares everything to their broken relationship, insulting her numerous times making her want to kill him.


We're both sabotaging our relationship.

Meanwhile, Leonard is finally sitting down with Penny and he agrees with her that he may have been trying to sabotage their wedding because he still doesn't think that he deserves her. Penny feels that that is the lamest excuse she has ever heard, but does understand what he is saying. She is worried that someday he might leave her for someone more like himself. In her own way, she is sabotaging them. Leonard wants them to stop being afraid of losing each other and just be together. Penny thinks that that sounds nice. Leonard tells Penny that he has loved her since the moment they met and that he'll love her till the end of time. That was the most beautiful thing anyone ever said to Penny. Then Leonard adds that Penny's beauty fills his heart with love and song. Now he is sounding Ccheesy. Leonard then drops to one knee and asks Penny to stay married to him. Penny now thinks that Leonard topped himself. They then run off to officially consummate their marriage.

Sheldon gives Leonard and Penny a wedding present for them; plane ticket to San Francisco and hotel accommodations. Lenny excitedly thank Sheldon, who states, "We're gonna have such fun!", which disappoints them (they don't want him to go too). Suddenly there is a knock on the door, it's Amy, fuming mad! She yells at Sheldon over posting a "Fun With Flags" episode where he talks about how much she has hurt


Amy is angry at Sheldon's behavior.

him and compares her genitals to Czechoslovakia. She demands he takes it down from the Internet. As she closes the door, he yells: "She watched it. I'm gonna get that girl back!" Then you hear Amy reply: "Only because you emailed me the link: "Watch this, it will make you mad!" Sheldon smiles saying: 'Yep, she still wants me!' He then happily skips down the hallway towards his room.



  • Title Reference: The title refers to Leonard and Penny's relationship that bounces between on extreme and another.
  • Taping date: August 18, 2015
  • This episode was watched by 15.23 million people with a rating of 3.8 (adults 18–49).
  • Total viewers including DVR users 20.78 million.
  • The Big Bang Theory was ranked #4 for the week ending September 27, 2015.
  • This episode aired in Canada on Monday, September 28, 2015.
  • In the United Kingdom, this episode aired on Thursday, October 29, 2015.
  • In Australia, it aired on Tuesday, October 13, 2015, with 2.01 million viewers.
  • Chuck Lorre's vanity card [1]
  • Episode transcript [3]


  • Jesse Schedeen at IGN - This episode was shaping up to be pretty great. It continued the relationship drama form last week's premiere and also introduced an interesting new wrinkle with the Wolowitzes. At the same time, it offered a welcome dose of humor to offset the darker aspects of the story. Unfortunately, "The Separation Oscillation" stumbled pretty hard in its final minutes. The quick, easy resolution to Leonard and Penny's marriage troubles didn't ring true. The show at least needs to do better when it comes to Sheldon and Amy.
  • IMDb user reviews [2]


  • Penny's hair starts to get longer in this episode.
  • Howard and Bernadette both knew about Leonard's accidental indiscretion with Mandy Chow for two years.
  • Leonard's kissing buddy from his North Sea expedition shows up; her name is Mandy Chow. She is played by Melissa Tang.
  • Sheldon and Amy went ice skating once even though Amy admitted to Penny that she couldn't ice skate due to extremely brittle ankles.
  • Sheldon gives Leonard and Penny tickets for a weekend in San Francisco as a wedding present and is going with them.
  • Fun with Flags is back.
  • Sheldon mentions that there are cable cars in San Francisco. Penny previously mentioned in "The Terminator Decoupling" (S2E17) how she liked to get drunk and ride the cable cars.
  • Penny's Posse returns again for the first time since "The Communication Deterioration" (S8E21).
  • Pop culture reference was made by Howard when he says "I'd like to Spongebob her Squarepants". Last time the cartoon show was mentioned was in the Season 4 episode "The Justice League Recombination" (S4E11) when Sheldon teased Penny's then boyfriend, Zack about watching a documentary about starfish coming back to life ("Was the starfish wearing boxer shorts because you might have been watching Nickelodeon" - referring to SpongeBob's friend, Patrick).
  • Bernadette only appears in two scenes of this episode and shares a small scene with a few gang members in this episode:
    • She only shares one scene with Howard in the kitchen at the Wolowitz House where she is very angry at him for keeping a couple of secrets, including Leonard's folly on the North Sea for two years.
    • She only shares one scene with Penny and Amy at Apartment 4B discussing about a number of things.
  • Bernadette shares no scenes with the other three men (Raj, Sheldon and Leonard) in this episode.
  • Amy and Penny share no scenes with Raj and Howard in this episode.
  • Sheldon references the dissolution of Czechoslovakia in Fun with Flags: Czechoslovakia split peacefully into the Czech Republic and the Slovak Republic by government edict effective January 1, 1993; this came about in the wake of the fall of communism in Czechoslovakia in 1989. There was no social and little political adversity to speak of between the splitting nations, and public opinion on the split was mixed at the time.
    • While Sheldon uses the line that "[Slovakia] invaded the Czech southern border" to make a pun (which succeeds in infuriating Amy), no such thing ever happened in fact. There was no fighting whatsoever in relation to the split, and there had not been any internal armed conflict for the duration of post-WWII Czechoslovakia's existence. Likewise, Czechoslovakia first arose in the aftermath of WWI in 1918 by political treaty of joint interest, not by conquest.
    • The Czech and Slovak republics share a relatively short stretch of border best described as south-east from the Czech side and north-west from the Slovak side, although residents mostly tend to think of the other country as being to the East and West, respectively (which is true for the bulk of either country's territory).
      • In fact, Austria makes up most of the Czech Republic's southern border.
    • Both the Czech and Slovak flags Sheldon is holding are current, correctly rendered, and held in the right orientation. The flag of Czechoslovakia, for the duration of its existence (1918-1939, 1945–1993), had been what is now the flag of the Czech Republic (the one Sheldon is holding in his left hand in this episode) (this lack of representation on the common flag was understandably a grumbling point with some Slovaks).
  • Amy has no speaking parts with Leonard in this episode.
  • Bernadette reveals that Howard is in big trouble about Leonard's North Sea incident.
  • Stuart is not featured in the scene where Raj, Howard and Leonard are arguing at the comic book store during this episode. Kevin Sussman wasn't needed for the story lines of that scene in this episode.


Penny: Hi.
Leonard: Hey.
Penny: You couldn't sleep either?
Leonard: Of course not.
Sheldon: Me either. But I just had a tickle in my throat. Not profound martial problems.
Leonard: What are we gonna do?
Penny: I don't know.
Leonard: Please tell me how to fix it.
Sheldon: I'm glad you asked. As I see it there is a simple solution. Your lips had a dalliance with the lips of another woman. It seems only logical that to restore balance to the relationship you should find another man and dally with him. And by dally, I mean some hardcore mouth in mouth action.
Leonard: Okay, that is the stupidest thing I have ever heard.
Penny: Actually I think he is onto something.
Leonard: You can't be serious. 'Cause I messed up and made out with a girl you're going to do the same with a random guy?
Sheldon: I'm currently single.
Penny: That's true. You are.
Leonard: What is happening?!
Sheldon: I'll tell you what is happening. I'm saving my best friend's marriage! (Turns to Penny and plants a big kiss on her; she wraps her arms around his neck and her leg around his waist!)
Leonard: *gasps* (waking up in bed from his nightmare)

(The scene of Howard entering the kitchen of the Wolowitz house with excitement when he sees a furious Bernadette preparing a tray of brownies).
Howard: Ooh, brownies for girls' night!
(Bernadette slaps her husband's wrist firmly just he reaches for one)
Bernadette: (she's very cross indeed) Hands off. I'm mad at you.
Howard: (he sighs) Look, I know it's a lot of money, but the guy at the store said in five to seven years, it'll pay for itself.
Bernadette: (she is asking Howard crossly) What will pay for itself?
(Howard shiftily gazes round the kitchen for ten seconds)
Howard: Doesn't matter. What are you mad about?
(Howard opens the fridge door)
Bernadette: (she explains to him crossly) I'm mad at you for blabbing to me what Leonard did on the North Sea, and I'm mad that I've had to hide this from Penny for two years.
Howard: (he's explaining shiftily) And you have every right to be mad about those things. So, why don't you let me handle the credit card bill this month, huh? I mean, don't even look at it.
Bernadette: (she's still very cross) I mean, if Penny finds out I've known all this time and haven't told her, she's gonna think I'm a terrible friend. I wish you never told me.
Howard: And I wish Leonard never told me. He's the bad guy here.
Bernadette: (she speaks crossly and quietly) I guess that's true.
Howard: And you let Penny marry him. (he scoffs) Compared to that, who cares if I bought a George Clooney limited edition manscaping kit?
(Howard shiftily leaves the kitchen whilst Bernadette has a huge angry think to herself)

(Skype ringing in the desk scene of Apartment 4A)
Amy: (extremely angrily) Sheldon, I don't think you understand how being broken up works. The only way I can sort through my feelings is if there is space between us. Every time I see you, it re-traumatizes me. I go through the pain all over again.
Sheldon: Well, hello to you, too.
Amy: (she is asking Sheldon angrily) What do you want?
Sheldon: I understand we're no longer a couple, but I would like to remind you that we made a baby together.
Amy: What baby?
Sheldon: A precocious little Internet show known as "Fun with Flags".
Amy: I'm hanging up.
Sheldon: Great. See you in about half an hour.
Amy: Sheldon, I am not doing "Fun With Flags" with you.
Sheldon: Why not?
Amy: Because we're broken up.
Sheldon: Sonny and Cher made it work. Their variety show kept going long after the divorce, and here we are still talking about them.
Amy: No one's talking about Sonny and Cher.
Sheldon: You must be thinking about Donny and Marie, 'cause you and I are clearly talking about Sonny and Cher.
Amy: Sheldon, this has to stop. I know it's hard. It's hard for me, too. But I've seen and talked to you more in the two days we've been broken up than in the last two months that we were together.
Sheldon: Well, if you want to see less of me, maybe we should go out again.
(Amy no longer responds to Sheldon as she is now off Skype).

Leonard: Well, hi. I'm calling about your marriage counseling services and I'm curious watch your rate is. Really? Um, okay. Is there any kind of discount for length of marriage? 'Cause we're talking hours here.

Penny: I guess my big problem is I never saw Leonard as the kind of guy who would do something like this.
Amy: Anybody can make a mistake in a weak moment.
Penny: What do you think?
Bernadette: (pretending to be guilty) Oh, I don't know what to think. But then again, I just found out about it.
Penny: You know, I fell in love with Leonard because he wasn't anything like the guys I was used to dating. I mean, I knew those guys weren't above cheating because that's usually how we met.
Amy: Come on, you know Leonard's not like that.
Penny: I want to believe you. I really do. Am I being naïve?
Bernadette: (nervous with guiltiness) Oh, I don't know. This is all so new to me. I'm still processing.
Penny: You know, he never would've done this when we first met. He's cockier now.
Amy: That's because you made him more confident.
Bernadette: (rather honest) You know, if you think about it, without you, he never would've grown into the person he is now. I mean, sure, more women might notice him, but I think it's better to have a guy be with you because he wants to be and not because he thinks he doesn't have any other choice.
Penny: I never thought about it like that.
Bernadette: (finally tired and very cross) Oh, me neither, not until just now.
(The subject is now closed as Bernadette now wobbles her glass and gazes round the room crossly)

Penny: So you said you had something to tell me.
Leonard: Oh, yeah, um. Do you remember when you accused me of trying to sabotage our wedding?
Penny: Uh-huh.
Leonard: I've been thinking about it and you might be right. But the good news is that I'm pretty sure I know why.
Penny: I'm listening.
Leonard: Penny, after all these years, I still feel like I don't deserve you.
Penny: Okay, that is the lamest excuse you'd could've possibly come up with. But I get it.
Leonard: You do?
Penny: Yeah. Sometimes I worry you're gonna wake up and leave me for someone more like you.
Leonard: I don't even understand why you're with someone like me. Why would I want to be with someone like me?
Penny: You know what I mean. And, you know, maybe the way I've been reacting was me sabotaging this too.
Leonard: (sighs.) well, how about we stop being so scared of losing each other and just be together?
Penny: That sounds nice.
Leonard: Good. (Both chuckle.) Because...I've loved you from the moment we met and I will keep loving you until the end of time.
Penny: Oh. Oh my God. That is the most beautiful thing anyone has ever said to me.
Leonard: Really? That's because you're beautiful, and your beauty fills my heart with love and song.
Penny: It's getting a little cheesy Leonard.
Leonard: Huh? If you think that was cheesy, buckle up. (Leonard takes her hand and drops to one knee.) Penny Hofstadter, will you please stay married to me?
(They kiss passionately)
Penny: Oh damn it. You topped it. Should we go to the bedroom and make this marriage official?
Leonard: Yes, please.
Penny: Okay.

Leonard: Hey.
Mandy Chow: Oh hi, Leonard. What's up?
Leonard: UH, do you mind if I sit?
Mandy Chow: Sure.
Leonard: So I've been thinking a lot about you and me and the boat
Mandy Chow: What about it?
Leonard: You know. what we did when we were drunk.
Mandy Chow: Oh no. Did I sleep with you too?
Leonard: No, we just made out.
Mandy Chow: Oh, well good for me. So what can I do for you?
Leonard: Um, okay. I just got married recently.
Mandy Chow: Oh, congratulations! To Sheldon?
Leonard: (rolls his eyes) Ha! That never gets old. No, no. To a girl. Anyway I told her what happened between you and me and she is concerned about us seeing each other at work.
Mandy Chow: It was just a kiss. Why would you even tell her?
Leonard: Because I didn't want there to be any secrets between us.
Mandy Chow: Is that really the reason?
Leonard: What else would it be?
Mandy Chow: I don't know. Sounds like you're trying to sabotage the relationship.
Leonard: No, I don't think so. Although, Penny did say exactly that.
Mandy Chow: Okay. Well, that is something to think about.
Leonard: You know, on some level I've always believed that I don't deserve a woman like her.
Mandy Chow: Oh, so you're gonna think that right here?
Leonard: I mean, she's really beautiful. She could have any guy she wants. Which is probably why it took her so many years to tell me she loved me.
Mandy Chow: Maybe you should talk to a therapist about this.
Leonard: Too expensive. You'd think I'd be used to women withholding their love. I mean, my mother did. I mean, no matter how hard I tried she just did not have any interest in me.
Mandy Chow: Imagine that.
Leonard: I wonder if that's why I have such a dysfunctional relationship with Sheldon. I had a dream the other night that I was in a cave and I was nursing a baby, but the baby had Sheldon's head on it.
Mandy Chow: And your wife is worried about me?

(The scene of Sheldon entering the door of Amy's apartment with a box of belongings. He is about to knock and suddenly stops himself for a second to think. He now knocks three times only once. He then makes a fist and Amy opens her apartment door in a big rage)
Amy: (with a giant fume of anger) What are you doing here?
Sheldon: I'm here to return your belongings. That's what people who've broken up do.
Amy: And You didn't do your compulsive knocking ritual so I would open the door.
Sheldon: On the contrary, you don't get to enjoy my charming eccentricities anymore. We're not friends with benefits!
Amy: Just give me the box.
Sheldon: W-Wait. Don't you want to go through it to make sure I haven't forgotten anything?
Amy: Fine. My old scarf.
Sheldon: You wore it the night we went ice-skating. Remember?
Amy: You mean the night that I went ice-skating, and you stood at the rail Googling the symptoms of hypothermia?
Sheldon: We made one heck of a team, huh?
Amy: Whose bra is this?
Sheldon: It's not yours? Oh, my. How embarrassing for both of us.
Amy: It's Penny's.
Sheldon: Hey, you broke up with me. It is none of your business whose naked bosom I'm smooshing around like pizza dough.
Amy: Good-bye.
(Amy's apartment door now slams on his face)

(Amy is watching Sheldon on a podcast of a new episode of "Fun with Flags").
Sheldon: Then the Czech Republic says to Slovakia, "I don't think you understand how being broken up works!"
(Amy opens her mouth with an angry shock)
Sheldon: Can you believe that? You would think that the Czech Republic would be trying to hold on to what it has given that it's not as young as it used to be. And I don't see any other countries lining up to invade it's southern borders.
Amy: I'm gonna kill him!
Sheldon: But enough about the Czech Republic. Let's talk about the time Moldova made Romania a birthday cake and Romania said it tasted good even though it didn't. And yet Romania gets dumped. I'll pause here while you mull that one over. I know, right?
(Amy puts the podcast screen down in a complete huff)

(The Apartment 4A scene during the ending shot where Sheldon opens the door and sees a mega-gigantically furious Amy who has just seen the video of what he has just done to her on "Fun with Flags")
Amy: (she shouts with an enormous tone of anger) How dare you go on the Internet and say mean things about me and compare my genitalia to part of Czechoslovakia?!
Sheldon: (he speaks to Amy nervously) You saw through that one, did you?
Amy: (she yells with one last gignatic burst of loud anger) I don't know what you were thinking, but take the video down now!
(Amy now slams the door in Sheldon's face and is now gone)
Sheldon: (he's smiling shiftily) She watched it. I'm gonna get that girl back.
Amy: (Yelling through the door out of vision) I only watched it because you e-mailed it to me with the subject line: "This is gonna make you mad"!
Sheldon: She was listening through the door. She wants me.
(Sheldon now skips off happily to his room)

(The shot in the hallway to Amy's apartment where Sheldon knocks on the table with Penny's red bra in his hand)
Sheldon: (knock, knock, knock) Amy. (knock, knock, knock) Amy. (knock, knock, knock) Amy. (sighs) Hmm. Tables work, too. Good to know.

Raj: I can’t believe you made out with Mandy Chow.
Leonard: Well, trust me, I wish it never happened.
Raj: And you knew about this this whole time?
Howard: I did.
Raj: And you didn’t think to tell me?
Howard: Leonard asked me to keep it to myself.
Raj: Let’s leave Leonard out of this for the moment. This is about you and me.
Leonard: Wait, wait, wait, how is my day-old marriage falling apart becoming about you two?
Raj: Hang on. What do I need to do to make you trust me?
Howard: You think it’s hard having one wife, try having two.
Raj: I bet you told Bernadette all about how he was screwing around with Mandy Chow.
Leonard: Oh, we didn’t screw around. We just got drunk and made out.
Raj: Whatever. It would have been nice to hear it from you.