Wedding Crashers (2005)

Guided by a set of "wedding crashing rules," Washington, D.C. divorce mediators John Beckwith and Jeremy Grey can charm their way into any wedding...and into the hearts of every bridesmaid...for one night. But at the biggest social event of the year, John breaks the rules and falls for Claire Cleary, the daughter of the United States Secretary of Treasury, William Cleary, and Jeremy is left at the mercy of her "stage-five-clinger" sex-crazed sister Gloria. Being there for his buddy, Jeremy follows John to the family's huge estate for a weekend that may even be too wild for these professional party animals.