All four couples go to West Eden for what they think will be optional counseling and lots of fun in the sun.
When they arrive they realize it is very strict and they must all participate in the couple's skill building exercises. Only one couple is considering divorce at first which are Jason (Jason Bateman) and Cynthia (Kristin Bell) but after they start they realize they all have problems. Dave (Vince Vaughn) and Ronnie (Malin Akermin) put work before each other. Lucy (Kristin Davis) and Joey (Jon Favereau) cheat on each other constantly and basically blame each other for all their unhappiness. Shane (Faizon Love) has recently divorced his wife whom he still has feelings for and has a twenty year old girlfriend he brings along named Trudy (Kali Hawk).
Through the ups and downs of the trip they all come to realize they love each other and are meant to be together except Shane who misses his ex wife, who he finds at the retreat for singles at East Eden. Shane decides to break up with Trudy and tells her to go be twenty and be free. Shane and his ex-wife decide to try again. Dave realizes he has been taking advantage of Ronnie and they finally go see the waterfall on the island she wanted to see. Jason realizes that he loves his wife and doesn't care if she can't have children and when Joey sees Lucy dancing with the yoga instructor he punches him and they realize they are perfect for each other. Then they tell the director of the program they don't need help anymore they figured it out and you realize it was all part of the plan