The film follows two sneaky guys who, apart from refusing to grow up, crash weddings to meet women. Things get complicated, however, when John (Wilson) falls hard for one of the bridesmaids (McAdams) they encounter whose family are American royalty - her dad is the secretary of the treasury! (Christopher Walken). Can Jeremy (Vaughn) help his best friend to get his act together in time to land the girl he never knew he always needed?