This movie focuses on 4 couples:
* The married with two young kids Dave & Ronnie (Vince Vaughn & Malin Akerman).
* The hyper-organized couple who cannot conceive Jason & Cynthia (Jason Bateman & Kristen Bell).
* The married since they were in high school couple Joey & Lucy (Jon Favreau & Kristin Davis).
* The recently divorced Shane (Faizon Love) and his new 20 year old girl friend, Trudy (Kali Hawk).
We see each of these couples go through their trials Ronnie is trying to remodel the house while Dave, who sells Guitar Hero, is uninterested. Lucy and Joey cheat on one another and seem to be waiting for the day their daughter goes off to college so they no longer have to pretend their marriage is real (though they do give good parenting advice to their daughter). Shane wants to buy a motorcycle to keep up with his new girlfriend. Jason and Cynthia are preparing a PowerPoint to show their friends, and Jason insists on checking Cynthias work. They set up their presentation at Ronnie & Daves house during one of the kids birthday party. The friends (minus Trudy, shes downstairs watching the magician with the kids) are all afraid theyre going to see another video about ball cancer but instead they see an island getaway. This paradise offers marital problem-solving, which the others are less keen on, but Jason and Cynthia drop the bomb that they are thinking of divorce, and ask their friends to please take the trip with them, because if four couples sign up, they can get the discounted group rate. Shane, Joey and Lucy seem to like the idea, but Dave and Ronnie argue that they simply cannot drop out of their lives right now, with all theyve got going on. Later on, Jason sneaks into Dave and Ronnies house, waking up everyone to plead with him to help him save his marriage. The kids say they overheard and they dont want their parents to get divorced, so they called Grandpa and he will come watch them. The couples are off.
They take a boat out to the Eden resort, and find out that their destination is Eden West, a couples skill-building retreat. Eden East, the other side of the island, is a singles bacchanalia with all the pleasures the flesh could want. Joey and Lucy are both intrigued by this other side of the island. They get to their cabins, marvel at the scenery and agree that this could be nice. The couples join at dinner and are told by Sctanley (with-a-c) that they can either have all the activities of the island (including the couples therapy) or none of it at all. After eating a delicious dinner, they decide it cant hurt to talk to a therapist for a little bit and then get on some jet-skis. They go back to their rooms and Joey tries to pleasure himself to a picture of a girl from the Eden East brochure, but is interrupted by a room service waiter.
The next morning, the couples meet Marcel, who has a plan for each of them. They will come to better understand each other in their marriage and find their spirit animal. They face each other and remove their masks, stripping down to their underwear (or in Shanes case, absolutely nothing) and telling each other that they love their bodies. Then it is time for therapy. One of the therapists is Ken Jeong, and he gets the pleasure of seeing Jason and Cynthia. Jason asks him if they have a better or worse chance of making it than other couples hes seen. He even pulls out his fingers in the shape of a gun and tries to get the therapist to give them a number from 1 to 10, but the therapist tells him to holster it. Dave and Ronnie go into their session feeling pretty good about themselves, but the therapist makes them think that maybe theyre just surviving instead of living and being happy together (a theme that goes on for the rest of the movie). Next is a visit with the sharks, where Jason spills the bucket of chum on Dave and Dave receives a minor scratch. Meanwhile, Trudy and Shane went on a bike ride, and Shane is struggling to keep up, which makes him start to realize his limitations in keeping up with her. Lucy and Joey go to get a couples massage, but they end up in different rooms, with masseurs of the opposite sex. Lucys masseuse is gay, and Joeys masseuse turns him on but tells him hes not getting a Happy Ending so he asks her to leave so he can calm himself.
That night at dinner, Trudy is mad at Shane, saying he promised her a fun vacation and they havent partied or anything. He consoles her by saying theyre going to have sex in the room, and they leave. Ronnie wants to hike to a waterfall she heard about, a place thats supposed to be really romantic, but Dave is too busy being a baby about his shark attack and heads to bed alone.
The next day starts with Yoga, with an instructor who is very touchy feely, and all about encouragement by patting on the rear (men and women). Lucy obviously finds him attractive, asking him to help her go into a deep stretch that involves a sexual looking position. Later at the spa, Ronnie ask Lucy what she thought she was doing, and how would she feel if Joey cheated on her. At Jason and Cynthias therapy session, we learn that Jason blames Cynthia for the fact that she cannot get pregnant. Jason talks to the guys about how sex is so routine and how it is frustrating.
Marcel tells the group that they must gather at the beach before sunrise the next morning, and not to eat or drink anything too late. Back at the cabins, Shane discovers that Trudy is missing. They decide she must have gone to Eden East to have some fun. Joey, whos been trying to figure out a way to get to Eden East since they got here, decides theyll take the canoes to try and rescue Trudy. Jason is against the idea, since hes a very follow the rules kind of guy, but they remind him that Marcel said they must all be there, so without Trudy theyd be breaking the rules anyway. Jason goes along, and criticizes Cynthias rowing. A storm suddenly comes up and Jason and Cynthia capsize, which of course was Cynthias fault as well. Finally, Cynthia jumps out of their canoe and swims the rest of the way to shore. She tells Jason that she is sick of being blamed for everything, and that shes done. She runs off into the woods, and the other girls follow her, telling the boys theyll meet up at the giant party. They boys go off and start discussing one anothers problems. Jason is too controlling, and blames Cynthia for everything. Shane should never have tried to be with someone so young, he should have made his marriage work. Joey wants a wife who will listen to all his stories and problems but he doesnt want to listen to anything she says. They do a very funny bit about going to Applebees all by yourself and having no one to talk to. Daves wife loves him, and just wants him to be involved, and he cant seem to find the energy or the attention. Kids and work and the remodel have gotten in the way of their being happy with one another. Meanwhile, theyve stumbled upon what they think to be an empty cabin
The girls talk about how at least Cynthia tries to make it work, while it seems like Lucy has just given up completely. They come to a clearing, where we see the waterfall Ronnie was talking about, and she laments that she cant be here with Dave. The Yoga instructor swims up from the other side of the island (naked) and offers them some island made sweet rum. Lucy and Cynthia want to cut loose and party, while Ronnie just wants to find Trudy and the boys and get back to the other side.
The boys discover that the cabin is not abandoned; it is actually the staff quarters, where Sctanley is playing Guitar Hero while the other guys watch. Sctanley threatens to call Marcel on the boys, but Dave makes a bet if Sctanley can beat him at Guitar Hero, he can call Marcel or take Daves bribe. If Dave wins, he gets to keep his money and Sctanley will help them get to Eden East. Dave of course wins and Sctanley gives them directions.
A few things happen at this party. Joey goes off with some young hot girls, saying that since he got married right after high school he never got to be young and have fun. Shane finds Trudy, and tells her that hes sorry, and she should go off and enjoy being 20. He is then found by his ex-wife, who says that she thought she wanted more out of life than just being with Shane. She tells him that she loves him, and wants to be with him again. Ronnie gets tired of the partying, and finds Dave, who takes her to the waterfall, and they talk about the fact that theyve stopped paying attention to each other. Cynthia and Jason reconcile, and Joey sees Lucy dancing with the yoga instructor and gets jealous, realizing he still loves her. He punches the yogi out (saying Encouragement) and tells his wife he cheated on her. She yells that she cheated on him, and they yell at each other about going to Applebees and kiss and make up.
The couples return to Eden West, after sun-up, and Marcel is angry that they did not follow the rules. Dave tells Marcel that they worked out all their problems and they dont need him to give them anymore couples skill-building, and Marcel smiles and agrees. He gives them woodcarvings of their spirit animals (Rabbit, wolf, honeybee, and donkey) and they go jet skiing.