The movie starts with a shot of the street covered in snow and ice with a boy on a bike doing the paper route. He’s throwing newspapers when a car almost hits him and swerves the other way hitting the fence. The driver gets out and spews a bunch of cuss words as the paperboy keeps delivering and ignores the man.
Inside an apartment, Miri (Elizabeth Banks) gets up to her alarm and knocks on the door telling her roommate Zack (Seth Rogen) to get up or she’ll be late for work. Zack sits up but lies back down. Miri puts on a pot of coffee and above it are a ton of bills owed but none have gone in the paid slot. She knocks on the door again to get him up and goes into the bathroom. Zack gets up and just before he goes into the bathroom she yells at him she’s using it and he freaks saying he didn’t know she was taking a shit. She yells at him the door was closed but he argues it wasn’t all the way closed. They argue some more and he leaves. Miri is soon in the car waiting for Zack using a hand warmer. Zack gets in the car and asks her what it is and she tells him. He gets an idea and snatches the hand warmer out of her hands and puts it in his pants. Miri freaks out but drives off in their hoopty (cheap, beat up car). As they’re driving Miri smells something and thinks it’s the car. Soon Zack is freaking out that the hand warmer is stuck under his balls and yells for her to pull over. She pulls over and he gets out taking off his pants to get it out. He gets back in the car and he tells Miri he thinks he burned some of his ball hair off. She laughs and drives off. She pulls up to the mall where she works and as she gets out asking Zack why he won’t help her pick out an outfit for later that night. He said she needs a friend and she says he is her friend but he says he meant a girl friend. They say goodbye and he drives the car to work.
At the Bean and Gone coffee shop, the manager is telling Delaney (Craig Robinson) he needs him to work black Friday. Delaney tells him how dare he do that and starts running off a list of racist names with days such as nigga Tuesday, or monkey Sunday because he’s black. The manager says he didn’t mean it like that and Delaney tells him he doesn’t care because when he gets his settlement from the post office he won’t have to work anymore. At that time Zack walks in as Delaney asks him if it’s racist that the manager asked him to work black Friday. Zack says yes and the manager starts yelling at him saying he’ll soon install a camera to see everything they’re doing saying he hates their ebony and ivory team and fuck them both. Delaney explains that he can’t work black Friday because he has to buy the flat screen his wife has been bugging him about forever. Zack says he can blame it on him because he took the day off because he’ll be really drunk on the day. Delaney asks why and Zack tells him Miri really wants them to go to their high school reunion together and Delaney teases him that they should’ve hooked up a long time ago. Zack tells him no they have a good thing going because she pays half the rent, does dishes, and they’ve known each other since first grade so it would be creepy. Delaney tells Zack that he’s known his wife since kindergarten and that they have a beautiful thing. Zack asks if he’s telling the truth and Delaney says no he hates her and they can’t stand each other.
That night at Bean and Gone, Miri is changing her clothes at the coffee shop getting ready for their high school reunion. She changes into an all yellow outfit and asks how she looks. Zack tells her she looks like Ronald McDonald and she gets mad going back into the back stock room. He asks to use her computer and she says yes but he has to hit it before turning it on or the screen won’t work. He hits it and asks her why she won’t buy a new one. She says she can’t afford it and as he looks on her screen he sees she ordered a vibrator on amazon.com asking her why she’s getting one. She tells him she can’t have orgasms with any of the guys she’s been with. As she’s changing, two young perverts see her underwear and laugh because she’s wearing a huge pair of granny panties. One of them takes his phone out and starts recording it. She soon changes into another outfit with hearts all over the sweater. She asks how it looks and Zack still doesn’t approve and she goes back to change again while the two perverts are still recording her. Zack asks her how can she afford the clothes if she can’t pay bills or get a new laptop and she tells him she borrowed the clothes from a friend who works at another store in the mall. He then says he’ll order a pocket vagina (vibrating) for himself and she says he should put his extra money toward the rent or some bills. She doesn’t think it would be smart if he bought one and he argues that he’s sick of using Jergens to masturbate. While still recording Miri, the phone is suddenly recording Zack’s butt because he caught them and they immediately cut it off and he kicks them out. Miri changes into a dress and he tells her it looks ok. They go back home to get ready while Miri is in the shower and the water shuts off. She yells for Zack and he goes in the bathroom trying to turn on the faucet. It goes off and he tells her they shut the water off. Miri then asks him to use water from the toilet. He lifts the seat and says there’s poop in there and she says no from the back of the seat. He gets it out and starts pouring it into her hair trying not to look as she hangs on to the shower curtain. It’s going fine until she falls on the floor trying not to let Zack see her. They soon get into the car and Zack tries to convince Miri that they shouldn’t be going since they haven’t done so well 10 years later. She tells him nobody there is any better than them but he cuts her down by saying yes they are. They then check with each other if they look any better than they did 10 years ago and they both give negative answers so then they drive off.
They arrive at the high school and go to check in. At the front desk the girl checking in the guests doesn’t remember either Zack or Miri and they tell her their names. Miri says her name is Miriam Linkey and the girl says she remembers stinky Linkey. She says to her no, that’s not true but they give her a nametag with her name and nick name on it saying stinky Linkey. Zack gets his but has no nickname on his and asks if he can have sex with the girl after the reunion telling her he eats pussy. She says no while handing them the sign in sheet saying she’s married with kids and Miri says that’s beautiful. Zack tries to convince her again but she says no. He hands her the sheet back and they walk to the gym. The girl looks down and sees he wrote ‘I love your pussy’ and freaks out. To make matters worse she turns around mad and Zack’s emulating eating her out. They both get to the gym and start talking and socializing when a guy who goes by ‘the other Zack’ and keeps giving Zack hell about it because they have the same name. Zack and Miri then go get drinks at the bar when Miri sees the high school quarterback that she had a crush on, Bobby Long (Brandon Routh) and goes to hit on him. Zack laughs at her for trying something pointless but she goes for it anyways. She sees him and starts talking to him and asks if he remembers her. Since they earlier took off their nametags he doesn’t know until she says she’s stinky Linkey. Bobby then remembers and tells Miri she looks good. She says thank you and starts hitting on him noticing that he’s not married and tells him neither is she. She asks about him and he tells her he has to go back to L.A. tomorrow and she says he’s gotten all big-time. Later by the punch bowl Zack sees a guy standing there named Brandon (Justin Long) and starts talking to him. He asks Brandon if he knows him and he tells Zack that he didn’t go to high school with them he just came with somebody else and says he came with Bobby Long. He tells him he wasn’t prepared to come to Monroeville (Pennsylvania). He asks Brandon what he does and he tells him he’s an actor. Zack asks what movies Brandon’s been in and he tells him he’s been in mostly spoofs that involve mostly men actually only men. Zack then realizes that Brandon’s a gay porn star and looks a bit shocked. Zack apologizes but Brandon says it’s ok because he knows Zack isn’t apart of his fan base. Zack asks how he knows and Brandon asks him if he likes pussy and immediately Zack says yes. Brandon then tells Zack that lets him know he’s not apart of his fan base. Zack then looks at Miri telling Brandon that Miri really wants to get with Bobby realizing that she doesn’t know Bobby’s gay. Soon Miri is asking Bobby back to her place after having a few too many drinks and he tries nicely to let her down. Zack and Brandon approach them while Zack tries to stop Miri from making a fool of herself. She still keeps propositioning him when Zack tells her what Brandon does and that Bobby brought him. Brandon sees Miri and then calls her granny panties because he saw the footage an hour ago that the two perverts recorded on their camera phone saying they got over 2 million hits. He then asks Bobby to take a picture of the three of them because he realizes that Zack’s ass was in the footage. Humiliated, Miri then realizes that Bobby’s gay and she leaves saying she’s going to drink until she falls over. For some odd reason Zack stays to ask about Brandon doing gay porn somewhat curious about his profession. But soon Bobby and Brandon get into a fight about Bobby being so secretive about their relationship while Zack stands in awe watching them argue. Brandon says he’s been putting up with Bobby being in the closet when they visit his mom and starts making a scene in front of everyone while people start looking as he yells that they’re gay. He keeps talking about how much he loves sucking Bobby’s dick and how much Bobby loves eating Brandon’s ass out and wants to know why he doesn’t want anyone else to know what they do in bed. Zack still stands in amazement that they fight like straight couples do. Somehow Bobby calms Brandon down and they kiss and make up when Zack leaves. Zack then goes to the table and sees another high school classmate he remembered while she looks pissed off seeing her husband flirting with a former cheerleader. Zack looks shocked that they got married and offers she can give him a hand job if she wants to get back at him. She first says she doesn’t want revenge but Zack says they can go in the girl’s locker room and she says she’ll do it in 10 minutes. They soon walk out as he zips up his pants showing that she did the deed.
That night Miri and Zack get home looking depressed about to drink beers and Zack tries to see the two in the granny panties site when their power goes out. Soon they go to a bar and start talking about how bad things are financially and how low they are on options. She then tells Zack that soon when they get home the heat will be cut off too since all the power went out and soon they won’t have a roof over their head. Miri asks Zack to extend his credit line again but he says he already did and he’s maxed out. He then says she could start by doing what they always said and be a hooker. She says she never thought things would get so bad that they would have to start having sex for money. He tells her that Brandon makes a lot of money for sex. Then the idea pops into his head and she gets excited. He tells her they could make a porno. Miri says that wasn’t the idea she had in mind but Zack keeps going on about how Brandon gets paid $1,000 each time he gets banged or gives a blow job. Miri still isn’t sure about it since it would be weird between the two of them. Zack mentions that the only people who do it are those with no dignity and no families. He says they both have no dignity and Miri’s parents are dead and Zack’s grandparents are dead nobody would care if they did porn. He also mentions they’ve known each other for a long time and would finally know what it’s like to have sex with each other. Miri accuses Zack of wanting to do a porno only to have an excuse to have sex with her. He says that’s not true it would be profitable since the porn industry does make a lot of money. They soon get home and keep talking about doing a porno while burning all their bills in the fire of their trashcan for heat because the heat was eventually cut off. They discuss how strange it would be having sex because they’ve known each other for so long and Miri says it would be like having sex with her brother. After much convincing, Zack finally gets Miri to agree to it.
On black Friday, Zack and Delaney are at the mall shopping when Zack runs the idea by Delaney saying if he takes the money for his flat screen to pay for their porn he can be the producer. Delaney seems hesitant because of his wife but Zack tells him he’ll get to see free tits and he won’t have to have sex. He says he’ll let him do the auditions and check out all the women willing to be in the movie. Delaney lights up to the idea and gives him his flat screen money agreeing to be the producer. Soon they’re all posting signs for auditions and looking for a studio. Delaney has a line of women waiting to show him their talents hesitant to see them because he’s married. He keeps trying to talk himself out of it while looking at different women. At the same time Zack and Miri are trying to come up with names of their porn such as spoof names from sci-fi flicks. They’re also using the water at Bean and Gone. Zack and Miri also find a place to shoot the film that used to be an old homeless shelter where the homeless used to go to the bathroom on the floor. The landlord tells them as long as they can clean it up they’ll be ok. They pay to rent it out and begin to set it up like a studio. Back at the audition, Delaney tries to respect the woman in the room and she strips her clothes off and he stares practically drooling. They also go to strip clubs looking for women and ask if any of them do anal sex and they find one, Stacey (Katie Morgan) who says she loves oral too. They decide to bring her on as part of the cast. They also interview different men who would like to star in their porn and find one guy, Lester (Jason Mewes), who says he has a special talent and tells Zack and Miri that he can make his dick stand straight up and not just out. He stands up and shows them and amazed they cast him. With the men they also pick up Barry (Ricky Mabe) as part of the cast. Zack, Miri, and Delaney also meet another girl auditioning who tells them she learned a trick at a bachelor party. She stands up and pulls her underwear down and shakes a bottle of bubbles and puts the blowing stick by her vagina and queef’s to make it blow up. It works and she pops it. At a loss for words, Delaney starts calling her Bubbles (Traci Lords). While playing recreational hockey (think intramurals), Zack is skating across the ice and the goalie gets mad because he doesn’t want to get hit. He gets fed up when he almost gets hit and throws down his hockey stick knocking out the guy trying to make a goal. He’s then told to sit out and sits next to Zack talking to him and Zack asks him if he used to videotape games in high school. His teammate, Deacon (Jeff Anderson) says he did only to sleep with cheerleaders. Soon Zack has a cameraman. After getting a full cast and crew they come up with the idea to call the movie ‘Star Whores’ and get started. Back at Zack and Miri’s apartment, the cast is there discussing who will have sex with who. They decide everybody will sleep with one another except when Zack says he’ll sleep with Stacey and Miri starts to look a little jealous. In order to deny her feelings she says she’ll sleep with Lester. Zack then starts to get jealous and says she shouldn’t do it or she’ll be uncomfortable but Miri says she’s slept with uglier guys than Lester and she’s ok with it. They then let it go and agree that everyone will have sex with everyone minus Delaney and Deacon (so he can shoot it).
They then go to the renovated studio and begin doing shots of them with dildos as guns dressed as the ‘Star Wars’ characters. They even show a pair of balls hanging where R2-D2’s opening is. They soon wrap it up and congratulate each other saying they’re looking forward to tomorrow when the actual sex begins. After they wrap it up Zack and Miri are the only ones left and begin talking about their sex scene. Miri makes Zack promise that things won’t get weird and he says they won’t. They then leave and Miri says she hopes things don’t go wrong and Zack asks what could go wrong with their porno. The next day the building is being demolished by construction workers just as the cast pulls up to see all their equipment and studio getting crushed. Zack and Miri yell to the head construction worker they already paid the man the full rent and then Zack says he’ll crush him. The construction worker tells him good luck because he ran off to Florida. Frustrated, they all go to Bean and Gone and are defeated they were tricked. Zack walks around pissed saying he knew he was a loser and gives up on it all while a patron walks in for a cup of coffee. Zack asks him what he wants and when the man tries to say something Zack interrupts saying it’s too late he gets a latte. Then as Zack looks out at the coffee shop he gets a vision and starts running around excited about his idea. He then runs to the back stockroom and sees the camcorder the manager set up in the back and gets the idea to use it to make a porno in the coffee shop since all of their equipment was demolished. They then decide to shut down the shop after hours and cover it with curtains. That night they shut it down and soon begin to shoot their first sex scene with Stacey and Lester. Barry acts as the sound crew and uses a hockey stick with a microphone on it. Lester begins the act by walking up to buy a cup of coffee while Stacey acts as the barista and offers him herself since she’s already topless. They then start to have sex while Barry pours coffee beans on them for effect. It seems to be going well until a drifter shows up drunk asking what time the place closes. Obviously he was still in the bathroom when Zack tells him they closed a while ago. He tells them he needs a coffee to drive home and Zack makes it on the house. While Lester and Stacey still have sex, Zack makes the coffee like it’s nothing. He then gets the drifter out and the cast and crew finish the scene. It goes well and they go to the next scene of Bubbles fucking Barry with a dildo while he seems to be enjoying it as much as she is. Delaney then says he’s disturbed at how much it’s turning him on.
The next night Zack closes the coffee shop shoving patrons out and gets the cast and crew to run in. This happens to be the night of Zack and Miri’s scene and it’s obvious that Miri’s nervous while Bubbles does her makeup. She keeps telling Bubbles that Zack and her are just friends and always have been while Bubbles doesn’t seem to be buying it. Then Zack walks in and Miri comments on how he shaved and he said he did it so he wouldn’t give her razor burn when he went down on her. She laughs saying she likes it and Bubbles leaves them alone. Miri tells Zack how proud she is of him and likes the ambitious look on him. They have a moment and then go to shoot the scene. The crew turns on the music and starts filming when Miri acts as an employee in a really short skirt, her bra out, and really high heels. Zack comes in with a delivery in cut off UPS shorts with a crate full of crème. They look uncomfortable the whole time and keep dancing around to the music while making sexual references about the crème and his going on Miri’s face. They keep moving to the other side of the room while the crew keeps pushing them along to have sex. Zack even tells Miri not to take her top off and almost none of their clothes come off. Delaney calls it the worst porno he’s ever seen while they all look waiting for some action. While walking, Miri reaches under her skirt and pulls her granny panties off throwing them on Zack trying to be sexy when it clearly isn’t working. Zack and Miri finally get on the coffee bean bag about to do it still hesitant. He asks her if she’s ready and she says yes. They kiss and Zack finally gets inside her and they begin having sex. But they aren’t doing it porn star style they seem into it like they’re making love. The crew looks at them because they’re so surprisingly gentle with each other and Deacon says they’re in a different world. Back to the duo they’re still having sex and enjoying it when Miri is about to climax Zack joins her and cum together. They lay in complete bliss while the crew cheers them on how great the scene went. They congratulate Zack and Miri on how well they did and leave to go out front. Zack asks Miri if she’s coming and she says she needs to take a break and he leaves. Miri lays on the bag of beans happy that she finally had an orgasm while Zack walks out the door and stands still thinking about what happened and seems relieved.
Back at their place, Zack and Miri talk about how well the scene went when Miri brings up that now she feels weird and did while they shot the scene. Zack asks if she meant weird in a bad way and she tells him no, she just didn’t expect him to do all he did sexually. Trying to dance around the issue, Zack tells her he did do a lot by acting, writing the script, and directing. Miri tells him she wasn’t talking about those things and he admits he knew. Just when they approach the subject of their romantic tryst, the power comes back on even though they haven’t paid one bill. Then they check the water and it comes back on. They jump in excitement and get a knock on the door. Miri answers with the whole cast and crew standing there. Zack asks if they talked to the landlord but find out they decided to pay their bills for the month because they were tired of Zack and Miri using their showers. They also appreciate the 2 for giving them a chance to do a porno and how they feel connected as a family. Delaney tells them they’re having a wrap party even though the movie isn’t done. He says they need a break and they begin dancing, drinking, throwing things off the back porch, and playing drinking games. Sitting on the couch, Miri looks at Zack and he smiles at her when Stacey suddenly sits next to her asking about the connection between her and Zack since Stacey has a sex scene with him tomorrow. Miri says it was good and Stacey interrupts saying she wanted to hook up with him that night. She asks Miri if it’s ok and Miri approves even though she doesn’t seem to be happy about it. Stacey jumps on Zack whispering she wants to sleep with him. He looks uncomfortable and whisper’s looking at Miri thinking about her. Stacey whisper’s she said it was ok and Zack looks shocked. He then stares at Miri as Stacey leads him to his bedroom looking upset that Miri approved. Miri also stares at Zack disappointed that he’s going to sleep with Stacey. They both close his bedroom door and Miri looks depressed on the couch.
The next day, Zack is directing the final scene for Stacey and Lester to have sex asking if she’s ok with it. She tells him she is because she’s constipated and normally anal sex loosens her up making her regular again. Zack says he takes an Ex-lax looking disgusted saying he’s never had that conversation before and goes to the back right when Miri walks in. Zack asks her why she’s there and she tells him she came to do the final scene with Lester and Zack gets upset asking her to come back so they can talk in private. He asks her what she’s doing and Miri says ever since they started the porn Zack has only wanted her to have sex with him while he does everybody else. He says that’s not true and brings up the other night when he knew they had something. Miri says it was just fucking and he angrily says they weren’t fucking because they felt something. Zack tells her they didn’t fuck they made love that night. Miri then asks if he was thinking of that when he fucked Stacey last night and he argues she did it to test him. Miri tells him she just let Stacey ask him he had the choice. Zack then calls her a jealous girlfriend and Miri yells she isn’t his girlfriend she’s just his friend. After hearing that Zack finally confesses that he loves Miri after all the years they’ve spent together. Defiant, Miri says they didn’t make love that night they just fucked and she’s doing the final scene with Lester. Zack gets so upset he leaves challenging her asking what if he didn’t fuck Stacey. Miri tells him but he did and without trying to explain Zack leaves. Miri almost cries and comes to do the scene when everyone looks at her because Zack drove off without doing the last scene. At the same time, Deacon is filming Stacey and Lester having anal sex underneath them when shit suddenly spills out all over Deacon’s face and camera. Deacon freaks out and runs outside with Delaney watching Zack drive off. Feeling guilty, later that night, Miri goes home to find Zack but sees his room is empty and that he’s moved out.
Three months later, it’s still cold in Pittsburgh when a guy in a mask and hockey uniform is getting shot with 2 paintball guns as a game during a fair. The 2 finish up and they’re the same 2 perverts that posted Zack and Miri on the Internet. The guy takes his mask off and its Zack covered in paint. Delaney walks up asking him if he used to work at the Bean and Gone and Zack looks excited to see him. During Zack’s break, he and Delaney talk about how things are and Delaney tells him he finally got his settlement from the post office. Zack congratulates him because he thought it was a joke. Delaney mentions that Zack still owes him money and asks Zack about the porno they made telling him it’s not finished. Still mending a broken heart, Zack tells Delaney he won’t finish it. Delaney says if he finishes it he won’t owe him anything and Zack agrees to clear his debt. At Delaney’s house, his wife (Tisha Campbell-Martin) starts yelling at him that he has another white boy in the basement why did he bring another one. He introduces Zack and she asks Zack if he thinks she’s fine. Delaney tells him to just say yes and he does. She offers to have sex with him until Delaney makes him go into the basement while the couple argues about her boobs sagging and Delaney’s balls sagging. Zack sees Deacon in the basement editing their porno while Delaney joins them.
The last scene is with Zack and Miri together and it kills Zack. He asks where the last scene is and they tell him Miri never did it. He feels terrible when Delaney explains how much the both of them did for the cast and crew they had how they should’ve seen what was right in front of them. Zack runs back to their old place and comes inside opening the bathroom door knowing Miri’s in there. She yells to close the door and he freaks saying he didn’t know she was taking a shit closing the door and tells her he loves her and that he never slept with Stacey. He only went in his room to talk about Miri all night when Lester walks out naked. Zack then says it’s ok if she’s sleeping with Lester because he loves her and would rather die than be without her and will wait a lifetime to be with Miri. Lester says they aren’t having sex he just moved in because Miri couldn’t afford the rent without Zack and she moved into Zack’s old bedroom because she missed the way he smelled. He says he just likes walking around naked. He then tries to get Zack to help jack him off but Zack declines and Lester goes back to bed. Crying, Miri opens the bathroom door and tells Zack she heard everything. He asks her why she’s crying and she tells him because she missed him so much. He picks her up and carries her to his old bedroom.