Vince Vaughn and Owen Wilson are enormously funny in this farce about two divorce mediators in the D.C. area who spend their leisure time crashing big weddings so they can seduce unescorted women. The early scenes deliver some rich send-ups of wedding culture (killing time during the ceremony, they bet on which tired Bible reading they’re about to hear), but the fun really begins when Vaughn and Wilson hook up with two pretty sisters whose dad (Christopher Walken) is secretary of the treasury. Before long the hustlers are vacationing with the secretary’s dysfunctional family, including his wife (Jane Seymour), who wants Wilson to touch her breasts, and his gay son (Keir O’Donnell), who wants Vaughn to touch him anywhere. David Dobkin directed; with Rachel McAdams and Jennifer Alden. R, 119 min. Burnham Plaza, Century 12 and CineArts 6, Chatham 14, Crown Village 18, Davis, Ford City, Gardens 1-6, Gardens 7-13, Golf Glen, Lincoln Village, Norridge, North Riverside, River East 21, Village North, Webster Place.