At the end of a season of successful crashes, Jeremy takes John to a wedding for a daughter of the U. 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.
Meanwhile, John attempts to court Claire, the maid of honor , but is interrupted by her hotheaded boyfriend, Sack Lodge Bradley Cooper , who is unfaithful and disrespectful behind her back. When Gloria invites Jeremy and John to an extended weekend party at their family compound, Jeremy tries to refuse due to him being extremely uncomfortable with Gloria. John overrules Jeremy to accept as it would be great to get to know the family. Jeremy reluctantly accepts, although he is suspicious that John only wanted to go just to get closer to Claire.
John and Jeremy become acquainted with the Clearys at their home: During dinner, as a means to get even with Sack for injuring Jeremy along with more time to connect with Claire, John spikes Sack's wine with eye-drops to make him sick and he spends the rest of his night throwing up in the toilet.
John and Claire continue to bond the next day on a sailing trip. The suspicious Sack calls his friend, Trapster, to privately investigate John and Jeremy. He then takes Jeremy hunting, where he is shot in the buttocks. While he recovers, John and Claire go on a bike ride to a secluded beach. Claire finally admits she is unsure how she feels about Sack and ends up kissing John passionately.
Meanwhile, Gloria tends to Jeremy's wounds and reveals to him that she is not as innocent or inexperienced as she initially let on. Jeremy realizes that he himself has been played and that he may be in love with Gloria.
When Sack falsely claims that he and Claire are engaged, John isn't fooled by this attempt knowing how unhappy she is with the former. Ready to confess everything to Claire about his feelings for her and convince her not to marry Sack, John is interrupted by Jeremy being chased out of the house: Sack has investigated and revealed John and Jeremy's identities to the family.
Betrayed, Claire turns away from John and the Secretary tells them to leave. Before leaving, Gloria and Jeremy briefly professes their love for each other. Over the following months, Jeremy manages to keep his relationship with Gloria a secret.
Meanwhile, John attempts to reach Claire but she refuses to see him. He comes up with a plan to see her by disguising himself as a waiter at her and Sack's engagement party. Concerned about John's behavior, Jeremy tries to talk some sense into him by reminding him that his last attempts to speak to her has failed and that he needs to accept the fact that it's over.
He also warns John against attempting to crash Claire and Sack's engagement party because of the high security Secretary Cleary has put on to ensure no crashers. Jeremy mentions that their only chance of avoiding jail time is to keep a low profile and stay away. John ignores the warning and attempts to crash Claire and Sack's engagement party by disguising himself as a waiter. He is caught by Sack who was alerted by his friends and beats John up.
He then warns John to stay away from Claire forever or else he will press charges against John. John visits Jeremy at his house to confront him for his absence and catches him having sex with Gloria. Betrayed, John walks out of the house and Jeremy follows trying to explain himself, while Gloria leaves to go to the engagement party.
Outside, John demanded why he didn't appear to stop Sack and learns that Jeremy had continued his secret relationship with Gloria.
John spirals into depression, crashing weddings alone and becoming nihilistic and suicidal. Meanwhile, as Claire and Sack plan their wedding, Claire's doubts grow. Jeremy proposes to Gloria and tries to ask John to be his best man , but a depressed John refuses. John visits Jeremy's former wedding crashing mentor, Chazz Reinhold an uncredited Will Ferrell , who convinces him to crash a funeral.
While there, he reconsiders his belief in love and marriage after witnessing a grieving widow. He rushes to Jeremy's wedding and joins the wedding mid-ceremony to Jeremy's delight. Claire is upset by his appearance, prompting John to profess his love to her and his regret for his past behavior in front of the congregation. Sack interrupts, but Claire finally tells him that she cannot marry him.
Senator Cleary supports Claire's decision and even admits his disgust over Sack's recent behavior. He also comes to the realization that unlike Sack, John actually cared for Claire and made her happy. Sack tries to attack John, but Jeremy intervenes to knock him out, and John and Claire kiss.
After the wedding, the two couples drive away from the ceremony together, discussing crashing another wedding together. Cast[ edit ] Owen Wilson as John Beckwith, one half of the wedding crasher duo; a bachelor who is a divorce mediator, riding high on his success with Jeremy.
Vince Vaughn as Jeremy Grey, the other half of the wedding crasher duo; an arrogant lothario. He remains a loyal friend to John. Christopher Walken as United States Secretary of the Treasury William Cleary, a big sailing fan and oblivious head of the dysfunctional but loving Cleary household; a generally friendly man, but punishes anyone who insults his wife or four children.
Isla Fisher as Gloria Cleary, youngest daughter of William Cleary; an emotionally unstable nymphomaniac who is obsessed with Jeremy. Jane Seymour as Kathleen "Kitty Kat" Cleary, the "social alcoholic" wife of Secretary Cleary and daughter-in-law of "Grandma" Mary Cleary; she appears to try and hit on younger men, including John and an ex-boyfriend of Claire this last one revealed by Todd. Ellen Albertini Dow as "Grandma" Mary Cleary, William's mother, Kathleen's mother-in-law, and the siblings' grandmother who lives in the compound; she is kind but obscene.
Keir O'Donnell as Todd Cleary, William and Kathleen's reclusive , hyper-sensitive son; a homosexual artist and family black sheep.
Bradley Cooper as Sack Lodge, Claire's testosterone -fueled, manly, and violent boyfriend who is obsessed with winning at any cost. Ron Canada as Randolph, the Clearys' Jamaican butler; he seems completely aware of Gloria's obsessive behaviors and does not approve of Sack's hotheadedness. Will Ferrell uncredited as Chazz Reinhold, the sage who passed on the wedding crashing rules to his protege Jeremy in When John actually meets him, Chazz is revealed to be a lazy man-child who still lives with his mother.