Top 30 Times the Big Bang Theory Cast Couldn't Keep a Straight Face

“The Anxiety Optimization”
Given how much flack Raj gets for how close he is to his dog, it’s unsurprising to see Howard invent an entirely new game to extend his mockery. He spouts off a piece of trivia and the idea is to determine whether or not Raj did or said something to his dog, or his girlfriend. The joke itself gets stretched across the episode, and depending on the scene, you can clearly tell some cast members had a hard time keeping it together. Johnny Galecki in particular can be seen smiling and laughing repeatedly, and we’re pretty sure it’s him and not Leonard loving the joke.

“The Spock Resonance”
Sheldon is all too excited that Adam Nimoy is coming to interview him for his new documentary film. With a knock at the door, he runs over and is more than excited to see the son of one of his heroes standing there. In an outtake for this scene, Jim Parsons can be seen grabbing the door handle and is unable to open it from his hand slipping off. This triggers a bout of laughter from himself, as well as Johnny Galecki and Kaley Cuoco. As hard as the actors work to get their lines, no one could be expected to hold it together when the set itself ends up being the problem.

“The Thanksgiving Decoupling”
Since most of us don’t work as actors in the television industry, it’s hard to know what goes through their minds as they are attempting to deliver their lines. When Howard is trying to convince the gang to come to the house for Thanksgiving, Simon Helberg breaks character and scolds Kunal Nayyar for apparently making him break. As an audience member, it doesn’t seem like there’s a clear reason for Simon’s break, beyond possibly a look on Kunal’s face. Whatever it was, it certainly got him and his castmates to chuckle and break the scene.

“The Peanut Reaction”
Across multiple talk show appearances, and even in the book about the show, multiple actors have commented on Kaley Cuoco’s uncanny ability to remember her lines. But even someone as talented as she is has moments where her memory slips. In a season one episode, Penny is trying to blackmail Sheldon into helping her give Leonard a birthday party. In a hilarious outtake, as Sheldon confronts Penny, Cuoco looks up at him and says “What’s my line?”. Parsons and Cuoco immediately burst into laughter, triggering a funny reaction from the audience. We love how even the simplest of bloopers can show how actors are just like everyone else.

“The Proposal Proposal”
Don’t ever think that anything you ever see or hear in a film or television series is by accident. Whether it was written on the page, or occurred in the moment, the director always has the option to do another take and what makes the final cut is carefully edited. In a scene from the Caltech cafeteria, we see Raj going to talk to Ramona - she’s one that triggered Sheldon’s proposal to Amy. In one take, after uttering a simple greeting, a large bang can be heard, spawning an outbreak of laughter from the cast and audience. We don’t get to see what caused it, but we do get to laugh along with them.

“The Spaghetti Catalyst”
There’s an unwritten rule when filming actors on a set when it comes to food. More often than not, they’re not supposed to actually eat anything (or much of it, anyway). This often has to do with keeping each take of a scene consistent when it comes time to edit the show. “The Big Bang Theory” was notorious for its scenes involving food. All of it was real, and prepared by a staff chef. During a scene between Sheldon and Penny, Jim Parsons forgets his line, and we just see Kaley Cuoco eating her spaghetti, and commenting on how good the food is. Her quip is met with laughter, and now we’re thinking about pasta!

“The Justice League Recombination”
Among the recurring characters on this show, Zack was always a favorite. He was such a contrast to the boys, and later the girls as well. With Penny having been the token “dumb blonde” for so long, it was certainly a change of pace to see someone whose tools weren’t even as sharp as hers. In a season four episode, Zack returns, and in an unexpected twist, our geeks start mocking Zack’s incompetence. During the sequence, everyone in the cast is laughing, except for Penny who knows the boys should be better, but can’t help themselves.

“The Space Probe Disintegration”
Sheldon and Leonard have decided to go with the girls while they shop. Instead of actually participating, they find themselves sitting in the store, and eventually succumbing to a deep conversation about their friendship. The original scene gets funnier as Sheldon uses Amy’s compact to help him clear tears off his face. The entire thing is already hilarious, but when we throw in the blooper, things are even better. In one outtake, Jim can’t help but smile, which triggers the rest of the cast to upend in hilarious laughter, with even Kaley thanking him for it.

“The Geology Methodology”
In the English language, there are countless ways a person can insult another. One common method often employed during a heated conversation consists of one individual informing another that they should engage in, to use a Sheldon turn a phrase, “coitus” with themselves. One such episode sees Sheldon and Penny in a passionate disagreement, leading Penny to make a similar comment using terms around sexual promiscuity. The aired scene goes over just as well as you would expect. However, in a behind the scenes clip, we see a long pause before Jim Parsons makes a huge smile, breaking Kaley into her own and a huge round of laughter and applause from the audience.

“The Paintball Scattering”
Sheldon and Amy are hesitant to read the feedback on their new theory. As they discuss their options, the audience and cast are treated to a couple of great bloopers that follow the same theme, in the same scene. At first, Parsons finishes his line, and there’s a noticeable gap. No one knows who is supposed to go next, which of course is funny to watch. Then in the same scene, only a few lines later, the exact same thing happens to Mayim Bialik. The cast is laughing and drinking fake champagne, to which Johnny Galecki makes a crack about the alcohol not even real, all while Kaley is making weird faces during the break.

“The Confidence Erosion”

Amy and Sheldon have a formula for figuring out their wedding so that both of their ideas are fairly incorporated. It starts well, but to no surprise, it turns into a disagreement fest. Amy frustratedly mentions potentially changing the flower girl to something less conventional. Shooting the scene, Jim Parsons couldn’t help but crack a smile after Mayim Bialik delivered the second part about the lack of flowers and presence of something less pleasant. The line is super funny within the context of the wedding planning scene. So we can see why Parsons couldn't resist smiling.

“The Emotion Detection Automation”

By the time Penny tells Leonard that her brother is coming to town during Season 10, he already knows about his illegal drug activities. Naturally, he’s not happy about her brother staying with them. Penny tries to help get her brother a job in the area. When she brings up the idea of him potentially working at the same pharmaceutical company as her, Leonard has a funny and creative response. Kaley Cuoco visibly tried not to laugh after Johnny Galecki delivered the line. But her smile eventually turned into laughter after all.

“The Escape Hatch Identification”

Sheldon provides abundant opportunities to get roasted throughout “The Big Bang Theory.” In many cases, it’s for his quirkiness or unconventional behavior. During one particular stairway scene in Season 10, he says something that exhibits kindness and social awareness, the latter of which especially often escapes him. Perhaps this comment doesn’t warrant a snarky response, but that’s what Leonard gives. After Leonard takes the shot at Sheldon, you can see Kaley Cuoco smiling and even starting to chuckle while walking up the stairs. When it was time to say her line, it quickly became evident they’d need a retake.

“The Scavenger Vortex”

If you’re on Bernadette’s team for a scavenger hunt, you better be locked in. All she wants to do is win. She shows that competitive edge during a Season 7 episode in which she finds herself teamed up with Leonard for a scavenger hunt. Things get a little rocky for Penny and Leonard when the teams are decided. Later, Leonard tries to bury the hatchet with Penny during the game. But Bernadette isn’t having it. Not the time, and not the place. This scene, which takes place at the comic book store, took several efforts to get right. Melissa Rauch and Johnny Galecki found the situation humorous as Rauch repeatedly shouted her line and shoved her co-star.

“The Retraction Reaction”

When Sheldon and Leonard find themselves at a crossroads with their work in physics, Leonard voices his disappointment and frustration to Penny. So, Penny suggests Raj and Howard cheer up Leonard and Sheldon. Raj is not in the mood for their negativity and what he describes as whiny, baby-like behavior. An outtake from this Season 11 scene showed Kaley Cuoco and Jim Parsons laughing. While Raj actually executed the line well, it certainly provided a reason for the actors to laugh. Howard’s presence during the scene is also worth nothing because at this point he’s an expectant father, visibly overwhelmed by impending fatherhood. Raj’s words certainly don’t help put him at ease.

“The Inspiration Deprivation”

Sheldon’s idea of ‘consoling’ someone isn’t quite up to par. In a Season 12 episode, Amy could use some emotional support from her husband. During a conversation with Penny and Leonard, Sheldon claims to have given it to her. But that doesn’t sound like ‘consoling.’ Penny’s ensuing line is seemingly sarcastic, poking fun at the lack of effort Sheldon gave to brighten up his wife’s day. Jim Parsons giggled after Kaley Cuoco said this line. Cuoco joined in on the laughing as well. This dialogue was a great piece of scriptwriting, and Cuoco’s execution brought it to life with flying colors.

“The Holiday Summation”

When a couple is watching a series together, there may come a time when one person feels tempted to watch an episode without their significant other. Depending on the situation, that could cause an issue. Penny watches not just one, but two episodes without Leonard. He isn’t thrilled about it, describing his fight with Penny to their friends. This produced a funny blooper in which the live audience reacted to Leonard’s line. This caused Cuoco, Parsons, and Bialik to smile and eventually break. Shooting another scene in Season 10, an “ew” sound from the live audience made Penny laugh. But we’re choosing the instance where more than just Cuoco laughed.

“The Relaxation Integration”

Stuart and Raj fight over Bernadette’s coworker, Ruchi, during Season 11. Raj goes behind Stuart’s back and isn’t totally truthful when Stuart runs into him and Ruchi. At one particular moment during the episode, Stuart’s line about the ‘big leagues’ of desperation produced a hilarious blooper. Kevin Sussman, who plays Stuart, delivered these words with great intensity and an irritated tone. The humor of the line itself along with Sussman’s execution of it caused Kunal Nayyar to crack up. What actually made the final cut for the episode was a calmer delivery of the line, which is also funny, but arguably not as funny as the blooper.

“The Holiday Summation”

Bernadette gives birth to Halley in Season 10. That same season, Howard brings his and Berndatte’s baby up to Leonard and Penny’s apartment. A laughter-filled blooper came out of this scene. The baby is asleep, so Howard asks if he can put her in the bedroom. Penny gives the okay. The blooper came after this as Simon Helberg tried to maneuver between a couple of chairs with the baby car seat in his hand. It didn’t go as smoothly as he hoped. The rest of the actors in the room laughed. The fact that the mishap occurred right after Amy offered help made it all the funnier.

“The Cohabitation Experimentation”

There’s snoring, and then there’s whatever that noise Sheldon makes while sleeping. Even Jim Parsons recognized just how silly he sounded while shooting this bed scene with Mayim Bialik. After a few funny-sounding snores and body movements, Parsons couldn’t control himself from laughing. This happened more than just once. He apologized and showed his frustration for not being able to keep himself together. At the same time, you could tell he was having a good time despite his several failed attempts. Unsurprisingly, what ultimately made the final cut for this scene was also quite funny.

“The Perspiration Implementation”

In Season Nine, Stuart invites the girls over to the comic book store to get their advice on how to bring more women through the door. When asked what he’s done so far, he mentions the “breastfeeding area” and tries to allay their concerns by telling them about the camera he had installed above them. In the episode that aired, this last comment creeps the girls out. However, in a great blooper, actor Kevin Sussman (who plays Stuart) can’t quite make it through his speech which ends up cracking up the rest of the cast in the scene as well.

“The Habitation Configuration”


Okay, so we have to admit that Sheldon handing Wil Wheaton a Wesley Crusher action figure and telling him to “feel free to play with yourself” - now that’s a great line. It still makes us laugh every time we watch that episode. And it turns out, Mayim Bialik liked it also. So much so in fact that the actress just couldn’t stay in character when it was her time to speak next. She was supposed to be angry - which we see in the aired episode - but in the blooper, she couldn’t even get started.

“The Zazzy Substitution”

Depending on your POV, feet can be sexy or gross, but not many people find them funny. However, watching Kaley Cuoco go to town on her feet in this season four scene was too much for Simon Helberg to handle. As we saw in the scene that made it to air, Howard is supposed to admonish Penny for scrubbing her feet wrong and then take over and show her how it's done. But in this take that ended up on the blooper reel, Helberg - although he tries hard to hang in there - can’t help but break as Penny scrubs and scrubs and scrubs away.

“The Holographic Excitation”

In Season Six, Raj had the very funny idea of dressing up as Indiana Jones’ mocha-skinned love child ‘Indian Jones’ for Halloween. The problem is that Jim Parsons and Simon Helberg thought it was a really funny idea also. This was a problem because every time Kunal Nayyar would try and get his lines out, those other two would keep cracking up. And if that wasn’t bad enough, once Parsons and Helberg were able to hold it together and keep a straight face, Nayyar just couldn’t get the line out properly for take after take after take after…..

“The 43 Peculiarity”

One of the things that makes this scene so funny is how long Helberg and Nayyar hold their positions with their faces just a couple of inches from each other. If you’re wondering how they managed to do it without laughing, well the answer is… they didn’t. At least not on the first take. We’re not sure how many takes they did, but we do know that at least one of them led to this great blooper in which they hold, hold, and hold, but eventually Nayyar cracks a smile. Helberg manages to hang on a bit longer, but not by much.

“The Fermentation Bifurcation”

In the Season Nine episode “The Fermentation Bifurcation,” the gang runs into Penny’s ex Zack at a wine tasting and gets to talking about science. Because, as Zack points out, he loves science and can even name a number of famous scientists including Mike deGrasse Tyson. Zack’s name mixup gets a smile of superiority from the geniuses - as the script certainly called for. What it didn’t call for though, was Kaley Cuoco bursting out laughing - which she did during one of the takes when Zack stumbles over the name mixup.

“The Discovery Dissipation”


Raj might just be the character most in touch with his feelings and the best one to give advice to the couples in the group. But that doesn’t mean they always want his advice. And in “The Discovery Dissipation,” each couple, one after the other, tells him exactly that. First, it's Howard and Bernadette, followed by Sheldon and Amy. But before they got a good take of Amy telling Raj to leave, there were a couple in which neither Nayyar, Bialik nor Parsons could keep a straight face as Raj doled out his relationship advice.

“The Love Spell Potential”

Howard is a master of impressions and in Season Six’s “The Love Spell Potential,” we got to enjoy a number of them - from Nicolas Cage to Christopher Walken. But when the girls return to the apartment where the guys are playing Dungeons and Dragons, Howard breaks out his Al Pacino impression to invite them to join in on the game. And yes, the characters are supposed to appreciate the impression, but if you look at the cast around Howard, you can see that these are real laughs - not acting laughing.

“The Fish Guts Displacement”

The episode in which Sheldon takes care of a sick Amy is filled with some of the biggest laughs of the series. We all remember Sheldon putting VapoRub on Amy’s chest and spanking her to “punish” her for lying about being sick once her condition had improved. Well, as big as the laughs from the studio audience were during these scenes, so too were Parsons and Bialik’s character breaks in the bloopers for each one. Bialik actually goes and winks at Parsons while he rubs her chest and Parsons loses it after each spank of her rear end.

“The 2003 Approximation”

It often requires multiple takes to get a scene right, and actors can break character numerous times before finally keeping a straight face for the scene that makes it into the episode. And then there are times when the scene that makes it to air isn’t the one where they don’t break, but rather the one in which they break the least. Case in point, Howard and Raj’s concert at the comic book store in Season Nine. As you can see in this blooper, Kaley Cuoco is breaking through pretty much the entire song. But check out the actual scene and you’ll see Cuoco holding strong when they first cut to her, but once Nayyar and Helberg hit those high notes, she breaks yet again.


Which “Big Bang Theory" makes you break the most? Let us know down in the comments!