Kat Ellis ( Debra Messing ) is a single New Yorker who returns to her parents' house in London to be the maid of honor at her younger half sister Amy's ( Amy Adams ) wedding. The best man is none other than her former fiancé , who unexpectedly dumped her two years ago. Anxious about confronting him and eager to impress him, she hires suave escort Nick Mercer ( Dermot Mulroney ) to pose as her boyfriend.
Wedding Crashers is a 2005 American romantic comedy film directed by David Dobkin and written by Steve Faber and Bob Fisher . Starring an ensemble cast led by Owen Wilson , Vince Vaughn , and Christopher Walken , and featuring Rachel McAdams , Isla Fisher , Bradley Cooper , Jane Seymour , the film has a notable cameo appearance by Will Ferrell .