NOTE: This spoiler was sent in by J.W.
The movie starts off with Joy (Cameron Diaz) and her fiancee Mason (Jason Sudeikis) coming out of their apartment drinking the smoothie she made them. As they go to work, Joy tells Mason they need to meet later to set a wedding date. Mason remarks that she is "making plans to make plans."
Joy is a trader. She is competing with Chong (Michelle Krusiec) for a promotion.
Jack (Ashton Kutcher) is the complete opposite of Joy. He opens his apartment door to find his "friend" Kelly dressed as a Girl Scout. She asks if he wants to buy cookies. He says he doesn't have any money. She says she doesn't have any cookies. She kisses him and they close the door. The next time we see them, Kelly is dressing and saying she wants a key to his apartment. Only because she doesn't want to wait in the hallways wearing all the costumes she wears when she comes over. She tells him that she doesn't want to be his girlfriend because he isn't " serious boyfriend material." She leaves telling him that next time she will dress as the grateful mother, whose baby was rescued from the fire and he will play the shirtless fireman.
Back at Joy's and Mason's apartment, Joy has planned a surprise party. Tipper (Lake Bell) remarks how it's a boring party and can they drink now. Joy says no and shows Tipper the Vegas plane tickets she bought Mason even though she hates Vegas. Joy basically spends her life trying to be exactly what she thinks Mason wants. Joy tells everyone to hide and when she turns on the lights to yell "Surprise." Tipper remarks " Oh, that's what you do at a surprise party. I better write it down for next time."
Mason comes home but before Joy can turn on the lights, he blurts out that he is stressed at work, and home is supposed to be an escape but it's not. And while he appreciates how she is trying new things in the bedroom with his butt, he wants to break up and since it is his apartment, she will be the one to leave.
Mason turns on the lights and asks if Joy is crying. Tipper yells surprise and Joy takes off.
At Jack's work (they make furniture,etc), Jack is too busy betting on a basketball game to actually work. His dad, the manager (Treat Williams), comes over and fires him. Jack says that he will play him a game of basketball to determine if he is fired. Jack and his dad play basketball while his dad tells his son that he needs to get serious about his life. His dad is about to win but Jack quits the games because he doesn't want to lose. Dad remarks that Jack always quits if he thinks he is going to lose. Jack's dad makes the shot and Jack walks away.
The next scenes intercut between Joy and Tipper at a bar and Jack and his friend, Hater (Rob Corddry), at another bar. Tipper said that what they need to do is hire some guys, go to Mason's house, hit his middle and while he is down on the ground crying " Why?" They will say " You know why!" Tipper and Hater both convince their friends to take a trip to Vegas.
At the Vegas hotel, Tipper is in her underwear and bra by the bathroom sink while Joy is in the shower. Jack and Hater enter the hotel room. Jack is wearing a pink boa and a long drink around his neck. Hater looks at the bed, is ready to relax and takes off his pants then goes into the restroom only to find Tipper standing there. All three scream. Jack is at the bar making a drink and tells Hater that he screams like a girl, unaware that the hotel double booked their room.
Tipper, still screaming sprays Jack with hairspray and starts attacking him. Joy comes out in a towel to help her friend, who is on the bed on top of Hater, Joy is about smash a lamp on him, when Jack comes in. He yells for them to stop but Joy attacks him and they land on the bed. She sees the boa and says " It's all right they're gay." Tipper calms down and they all realize the hotel just double booked the room. Jack tells her they are not gay and the women quickly get off them and cover themselves.
At the lobby, Joy says she will handle everything. The others watch as she goes to the manager and tells him, you know what I'm going to tell you and I know you will say there is nothing you can do but we both know in the end you will do what I want, so just enter your code in the computer so my day can be right again. The manager says that since she is scaring him, here are two penthouse rooms. Joy walks back triumphant.
Jack tells her to watch what he can do. He goes over to the manager and acts very nice, telling him that she is great three weeks out of the month but on the fourth week it's time to pay the bill and it's odd how someone named Joy can act like that. Jack comes back holding a ton of VIP passes, etc.
They all end up is a stretch limo. Hater and Tipper cannot stand each other. He calls her a stripper while Jack is trying to hit on Joy. Wanting to get away from them both, Tipper and Joy get out. Jack pops his head out of the sunroof and asks Joy to join them. She says that they need to stop here and plan their assault on the strip. Jack remarks " You're making a plan, to make a plan." Which really irritates Joy and back in the Limo they go. Joy and Jack drink, have fun and get to know each other. Both admit the real reasons they are in Vegas. At the betting table, Joy asks Jack to throw the dice but he wants her to do it. This is a recurring theme in the film. Jack never wants to bet if there is a chance he will lose. They win money and go to another bar. Joy stands on the bar and tells everyone that has ever been fired or dumped to say you after she says screw. Joy gets wild and admits that she isn't usually this fun. She uses a knife to cut the top off the champagne bottle.
Tipper and Hater sit together at a table. Hater tries to pick up two women. Tipper tells the women that Hater is married, so Hater says that Tipper is his lesbian sister. The next few scenes are a blur. We see Joy and Jack briefly in the hotel room. Joy wakes up the next day with Jack 4 Ever in a heart drawn on her hand and a wedding ring. She sees a note on the mirror " Wifey, I'm at the buffet."
On the elevator ride down, Joy scolds Tipper for not stopping her. Tipper, who looks a mess, says that she threw up in her purse.
They all sit at the table. Joy says she needs coffee and Jacks says " What mine is yours." Tipper takes a bit of Hater's food which he squashes out of her hand. Tipper says if she could make someone dead using her mind, it would be him. Joy asks Jack to meet alone. Joy goes over and plays a slot machine, Jack comes over and starts talking to her. Joy asks if he is dumping her because she wanted to dump him. Jack admits that she would be a lot of work. Joy gives him her card and tells her to email her so they can get an annulment. She leaves her quarter with him and he plays and wins 3 million dollars. Joy is happy and stands with him for the picture. Jack tries to get away from her when she says " What's yours is mine, remember?"
At the court room, Jack is being represented by his lawyer Hater (who is a very bad lawyer and never won a case.) The judge asks if there is any proof that this marriage isn't a sham. Joy produces a note with jack and joy on it, and a huge picture of them. She hold them up for the judge and pushes the evidence in Jack's face then she shows them part of the wedding video where Jack and Joy are speaking to the camera and Hater is in the background. The Judge cannot believe that the lawyer was there at the wedding.
The judge sentences them to live together for 6 months, go to weekly counseling and to try to make the marriage work. He admits his wife infuriates him and sometimes he wants to set her on fire but he doesn't because he loves her and it's illegal. He says that if they come back and want a divorce, he will give it but if they don't try he will freeze the money and tie it up in litigation that they will never see any of it.
Joy and Tipper arrive at Jacks apartment. Tipper is recording everything on her cell phone for evidence. Joy acts happy and they go upstairs and give each other an awkward kiss. Hater is there. He knocks something out of Tipper's box and it falls downstairs. Jack picks up joy, carries her over the threshold and drops her saying she's a little heavy. Joy says she ran the marathon, she can do this then she sees the disgusting hair filled bathroom. She asks if he keeps monkeys in there. Jack says he is saving the hair to make her something nice.
That night Joy asks where the bedroom is. She wants to sleep in the bed and Jack on the couch. Joy opens the door and the bed falls out. It stinks. Jack says it smells like him and a couple of other people. Joy starts spraying stuff on the bed, her foot touches the bed so she sprays herself and asks if she can have the couch. Jack says no.
The next scenes are of Joy and Jack trying to annoy each other. He pees in the sink when she takes too long in the bathroom. He puts energy powder in her smoothie so she goes to work completely pumped and excited. She starts yelling " Yeah, let's sell some stuff!!!" in the meeting and the manager is impressed with her enthusiasm. She gets on the trading floor and can't concentrate, she throws her bottled water on her and realizes she's been had. Jack throws stinky clothes in the bed,. Joy lights candles to combat the stink. Joy lifts the toilet seat up and down to show him how to operate it. Joy goes into the bathroom one night and falls in the toilet. Jack smiles and pulls the entire toilet seat from under his blanket. After making him wait again to use the bathroom, Jack and Hater remove the bathroom door. When asked, Jack says they were robbed and only the door was stolen.
At their first counseling session with Dr. Twitchell, she asks Jack what his hobbies are. He says listening and loving Joy. He says he carries around a notebook because she says important stuff. Joy says her hobby is staring at Jack and that while others may be repulsed by Jack's stinky clothes, she loves them and wants to roll around in them. Irritated, Jack says " I love her candles!" Dr. Twitchell tells them she knows they are lying and they need to make an effort if she wants them to tell the court they are trying.
During intercuting scenes, Hater tells Jack to get evidence that Joy doesn't want the marriage to work and the money will be his. Jack says that is a great idea and why didn't he think of that before. He says because he is a bad lawyer. There should be a law for how bad a lawyer he is but then again, he wouldn't know about it. Tipper tells Joy to catch him cheating and she will get the money.
Joy has a couple of women go over to the apartment. They ask if they and their friends can wait inside because they are locked out of their apartment. Jack is happy and calls Hater who tells them it is a trap. Jack asks Hater to bring over a bunch of business type guys that Joy will like. Joy comes home thinking Jack will weaken but instead his friends come over, along with the business guys who are told not to look at Joy because that will make her interested. Jack's friend Curtis comes over and can't believe how hot Joy is and what is wrong with Jack! Two stripper cops come over. Everyone is having a great time, except Jack and Joy who end up in the bathroom trying to get away from the fun since they can't have any themselves.
Joy hits a sore spots when she tells Jack that a relationship is too much for him to deal with, he isn't serious boyfriend material (Something like that) so Jack says she is still in love with Mason because she wears his ring. She says she wears it because she can't wear the gumball machine ring he bought her. Joy admits that she spent all her time trying to be what Mason wanted instead of being herself and she still didn't feel like she was good enough for him. Joy finally takes off the ring and hides it on a bathroom shelf.
Jack gets Kelly to call Joy pretending to reschedule the counseling session since if they miss they will be in contempt of court. Joy relaxes in the bathtub while Jack steals her wallet and goes downstairs to hail a taxi. Joy hears him and calls the Dr. Knowing she's been had, she runs downstairs and gets in a taxi realizes she only has five dollars. Jack is in the street waving her wallet in the air. She shows the taxi driver one boob (not on camera) and he allows her to stay. They get caught in a traffic jam. Jack skateboards by. Joy runs off buys 10 for a dollar oranges and starts throwing them at him. She manages to get on top of a double decker tour bus. She sits down only to have Jack appear. She squashes him against rail. They get off and dash through the park over picnickers and grabbing stuff from them. Joy drinks champagne They both grab bread sticks and beat each other. They climb over the wall and manage to get to their appointment on time but completely sweaty, muddy and out of breath.
Jack and Hater sit on a park bench. Hater has another idea. He slaps Jack who doesn't understand and starts beating him up. We see Jack enter meeting with Joy and the Dr. He is wearing big glasses. When he takes them off, we see his black eye. He says he fell many times into a doorknob. He says all this in a feminine way, pushing the hair behind his ear. Finally, he says that Joy did it because he didn't put the toilet seat down. He goes on and on until Joy shows a video on her camera phone of Hater and Jack fighting. With that cleared up, both start yelling and complaining about the other. The Dr. is pleased because they are arguing and finally acting like a married couple.
Jack comes home and finds Joy having dinner with his parents. Jack begs Joy not to tell his parents the truth. She agrees as long as he puts the bathroom door back and the toilet seat down. His parents are very happy with his choice. Joy compliments Jack on the table he made. His father puts him down pointing out a mistake. Joy says that Jack could sell furniture but the dad says that he never finished anything. He couldn't even finish the table. The parents invite her to a birthday party at the park the next day.
Jack decides to find Joy's weak spot since she found his (his parents) he gives the ring to Mason, who mistakes him for a waiter, and says that Joy thought she wasn't good enough for him and she has completely changed and is doing great. She even bought his uncle some weed. Mason thought she would be miserable and gaining weight but Jack says she looks good and won't be on the market for long and tomorrow they would be at the park.
At the park, Joy sees Jack coaching a little league team, they both discover they love Indiana and that Jack's best friend is his niece who he tells everything to. They talk a little and walk with the niece when Mason shows up wanting to go somewhere and talk but Joy can't, so Mason leaves.
At work, Joy is completely behind when her boss appears. He tells her to bring her husband to the retreat. Hater comes up with a plan for Joy to sign a document at the retreat that gives all the money to Jack. If she doesn't, he will expose everything at the retreat. The agreement is written on torn out piece of paper which Hater says he will laminate.
At the retreat, Chong is there with her boring husband and trying to impress the boss, while Jack is over at the managers table, laughing with everyone. The boss tells him to get out of his seat. Jack asks his name and the boss replies " Richard Banger." Jack laughs and says you're Dick Banger? You have just provided the table with jokes for the rest of our lives. Instead of getting angry, the boss laughs and says Jack's name is " Jack Off." Jack stays in his seat while Chong and her husband are forced to move down.
They all play games and have fun. At the casino theme dance afterwards, Joy walks in the room and the men turn to look at her including Jack who is entranced. He is wearing a tag that reads " Hello my name is Joy's Bit*h" Joy takes it off and pats Chongs back, sticking the name tag on there. The boss laughs and says if he had known Joy was this fun, he would have promoted her long ago. Jack makes Joy show everyone her champagne bottle trick. Hater keeps calling and paging Jack to make her sign the agreement but he can't. Hater yells that he cannot believe he is falling in love with his wife.
They are back at a betting table just like in Vegas but this time Jack is confident enough to roll the dice. He does, they win and he immediately stops betting.
Jack wins the spirit award and goes up on stage and tells everyone that he and Joy didn't know each other long before they got married but when you know, you know and they didn't have a wedding dance, so they would have one now. They dance and for the first time, actually kiss, instead of the stiff quick pecks they would give each other to act like they were trying.
They walk outside and talk to each other. Joy admits that she would bet on Jack anytime. She tells Jack the last time she was happy was before Mason, when she got on a ferry and went to a lighthouse and walked on the beach all alone, no job worries. Just herself making herself happy. Jack remarks that he has seen the picture she keeps of the lighthouse.
In the hotel room, Jack unzips her dress. It is clear both want each other but Jack stays awake on the couch and Joy stays awake in her bed.
On her way to court for the last time, Joy runs into Mason, who gives her the ring and says she is good enough for him and he wants her back. Joy is stunned that Jack gave her ring to Mason. Thinking Jack, doesn't care, Joy takes off.
In the courtroom, Hater draws a picture of a hand sticking the bad finger and shows it to Tipper. The Dr. testifies that both have many problems but they are perfect for each other. It is revealed that Jack has opened his open shop. Hater says that the money should be split. Joy has an objection. Hater whispers " Gold digging Bit*h." But Joy doesn't want the money only a divorce. Hater jumps up exclaiming that he finally won a case. He flicks off the courtroom and says " How do you like that Bit*hes!" Something like that.
There is a party at Jack's house. Hater is drinking asking anyone if they need a lawyer. Jack sits there depressed. Curtis asks for Joy's phone number.
There is a scene of Jack at work, actually working. He listens to an ipod, so he is completely focused on his work. His dad looks on impressed. He has dinner with his parents. His dad does not say anything bad about the table they are eating on. He is happy that Jack finished something (the table) but he is upset that Jack let Joy go.
In a meeting, Joy is promoted but turns it down saying she'd rather do nothing then something she doesn't love. Which is the exact same thing Jack said to Joy when she remarked that he didn't have a job.
Jack goes to Tipper trying to find Joy but Tipper doesn't know. She just knows Joy quit and left. Jack finds the lighthouse picture under the bed and wants to go find Joy. Curtis says that they should both go so Joy has a choice. Hater yells after him that he is running to find his future ex EX wife.
Jack finds Joy on the beach. He tells her she left this behind and he wanted her to have it. He also says that he had to go to five lighthouses before finding her since she never said which lighthouse she went to. He says that she was the only person that ever bet on him and asks her to marry him and she says that she tried so hard not to please him that she finally ending up being herself and she would marry him.
SIX MONTHS EARLIER. The wedding video shows a drunken Jack and Joy with Hater and Tipper making out in the background.
The final scene after the credits start is of Tipper and Hater going to Mason's house and Tipper punching his stomach. Mason goes down crying " Why?" Tipper says " You know why!" She hi-fives Hater and they run off.