At least one of the characters in "American Wedding," which is presumably the last of the series and should well be if the producers want to end on a successful note, uses her mouth for better things than talk. In a restaurant, Jim is set to ask his girlfriend Michelle to marry him after a three-years' courtship, Michelle, thinking that he is propositioning rather than proposing (and none the worse for the thought), crawls under the table to set the tone for the show. "American Wedding," which brings to mind the gag "Do you want sex or do you want to get married?" is not so much about marriage as it is about sex, since most of the latter appears freely available to the folks who ultimately attend the ceremony including the septuagenarian grandmother.

The movie is populated by a diverse lot, each representing a point of view or, even more telling, a basic type of character. Jim, for example, is frequently bemused and acts throughout as a straight man for the barbs of his fianc, his less-than-favorite friend Steve Stifler, his classy and intellectual buddy Finch (Eddie Kaye Thomas) and even his unflappable but literal- minded dad. As the guests gather for the big affair, which is to last a weekend, Stifler takes particularly note of the bride's sister, the remarkably comely, corn-fed Cadence (January Jones). Competition for her attention builds between the intellectual Finch and the vulgar Stifler, the latter, understanding what he must do to win her heart (and more), behaving against type like a gentleman.

With an assured sense of comic timing, director Jesse Dylan moves Lloyd Ahern's camera from the groom's capacious quarters to the wedding hall, honing in on activities, some traditional and honorable, others often gut-busting funny. While nobody, however horny, winds up making love to a cake as Jim had done a while back to an apple pie, considerable steps are taken by the parties on the one hand to set a good example so that everything goes on schedule and on the other hand to perform activities that put a damper on the festivities. Among the former is Stifler's patient focusing on the bride's family's Briard who accidentally swallowed the ring that Stifler was safe-keeping. His recovery of the jewel was not without repercussions that you can well imagine. At the same time that Stifler acts in the interest of harmony, he is looking out for number one: his goal, the conquest of Cadence (which appears far from difficult), is frustrated by Stifler's need to brag to his pals about his prowess with women.

This is Seann William Scott's movie. While Eugene Levy, last seen on the screen as a bemused, aging folk singer in the wonderful "A Mighty Wind," acts right according to type as the dad who can be counted on to embarrass his son, Scott is a tsunami of energy, a chain reaction who repeatedly follow up each incident of bad behavior by trying to redeem himself. Scott, then, provides the momentum that edges the episodes forward to a coherent, often riotously funny story.