Against the advice of his best friend Ted (Michael Weston), Anderson (Jason Biggs) proposes to his girlfriend, Vanessa (Audra Blaser), publicly whilst dressed in a cupid costume. The shock of the proposal leads to her instantaneous death. Utterly devastated and distraught, Anderson quits his job and goes into mourning. Anderson is still obsessed with his perfect (and dead) former girlfriend and to help him move on, Ted persuades him to give romance one more try. To placate his friend, Anderson agrees. Right after, waitress Katie (Isla Fisher) comes over. On a whim, Anderson asks Katie to marry him, and to his utter astonishment, she accepts his proposal. Anderson and Katie now decide to take things slow, the same day she moves into Anderson's apartment. Meanwhile Anderson is feeling guilty as when unconscious he spoke to his former girlfriend, the late Vanessa. However he goes ahead with plans to meet her parents, and to bring Katie to meet his parents. The pair soon begin to get on well with each other and, although not the smoothest of meetings, the parents have no real objection to the marriage. Katie's father, Smitty, breaks out of jail to walk her down the aisle. He arrives at his ex-wife (Katie's mother)'s house and through their long lost passion for one another, their love sparks again, much to Stuart's (Lois's current husband) discomfort. After a falling out over Anderson's late girlfriend, Anderson and Katie's relationship looks to be over. This pivotal moment in the film leads to the pair finally declaring their fondness of one another. In line with the film's spontaneous feel, the couple suddenly run off to Atlantic City, with help from Ted. Now Anderson, Katie, Ted and the rest of the party are driving to Atlantic City, in a car from the car dealership where Ted works (under the pretense of test driving the vehicle). Katie's ex-boyfriend, William, tries to persuade Katie that they should be together. He proceeds to assault Anderson on the way to their wedding. Ted's boss reports the car stolen, and in an unfortunate event, they crash into a police car, resulting in their arrest. Meanwhile, Katie's parents know where they're headed and make their way there, stopping to rob the Tuxedo Depot in preparation for the wedding. Katie's parents are also arrested for robbing the store. They all end up in the same police station, and Anderson's parents also turn up after he calls them. In a lucky turn of events the group is able to escape from the station after stealing an officer's gun and locking them in a cell. At this point Anderson and Katie establish for the final time that they want to get married and for the first time, the whole group is in favor. Now in a police van, which the policemen let them use, they drive to Atlantic City and Anderson and Katie finally get married. However, as soon as they step outside they are all arrested. Anderson and Katie spend their honeymoon in jail and bribe a judge with a blender they received as a wedding present.
