Two guys find out the hard way that sneaking into the wrong party can cause serious problems in this comedy. Jeremy Klein (Vince Vaughn) and John Beckwith (Owen Wilson) are a pair of longtime friends who work for a law firm, helping contentious couples mediate their divorces. Their job has given them a cynical attitude about marriage, and as a hobby each weekend the two make a point of crashing weddings reception, where they load up on free food and booze and try their luck at seducing the bridesmaids. When William Cleary (Christopher Walken), the nation's Secretary of the Treasury and a possible candidate for the Presidency, announces his daughter is to wed, the nuptials are billed as the social event of the year, and Jeremy and John decide they must attend the reception. However, John makes the mistake of falling head over heels for Claire (Rachel McAdams), the bride's sister, while Jeremy attracts the attentions of a woman he'd prefer not to be involved with, and soon their romantic peccadilloes get them in very hot water.