John Beckwith (Owen Wilson) and Jeremy Grey (Vince Vaughn) are divorce mediators in Washington D. C. who "crash" wedding parties to meet and bed women. At the end of a season of successful crashes, Jeremy takes John to a wedding for a daughter of the U. S. Secretary of the Treasury, William Cleary (Christopher Walken). Once inside, the pair set their sights on Cleary's other daughters, Gloria (Isla Fisher) and Claire (Rachel McAdams). Jeremy ends up having sex with Gloria on a nearby beach during the reception. Gloria is possessive and quickly becomes obsessed with Jeremy, and Jeremy urges John to escape the reception with him.