A bawdy summer comedy for adults and mature teens, this movie features rapid-fire dialogue and sincere affection between best-friend leads and strong chemistry between the actors who portray them, thereby elevating what could have been a brainless ode to never growing up into a very funny, genuinely warm-hearted, but uneven and morally ambiguous movie.

John (Owen Wilson) is an optimistic womanizer with a romantic side as big and confused as his monologues about love, while Jeremy (Vince Vaughn) cloaks his insecurities in a brash, party-boy exterior. At work, the two are mediators for couples heading for divorce, but their real passion is crashing weddings. They tell themselves they do it to pick up vulnerable women who are drunk on the promise of true love and the longing for a wedding of their own. They never acknowledge to themselves or each other that a large part of appeal is the way weddings give them a sense of being part of something — of their own connection (they seem to be all the family each other has) and at least pretending to be a part of the families whose happiest moments they are sharing.

We first see John and Jeremey mediating a divorce settlement between snarling soon-to-be exes Dwight Yoakam and Rebecca De Mornay. The duo soothe a dispute over the division of the frequent flier miles by explaining that “the real enemy here is the institution of marriage.” Then we hear a rapid-fire monologue by Jeremy about the horrors of dating, and we speed right into the weddings. A brilliantly edited montage shows John and Jeremy as the ultimate guests, with a name and a backstory for every situation and ethnic group. They know wedding cliches better than a clergyman, placing bets with each other on whether the Bible reading will be Corinthians or Galatians and whether the bride will be a crier.

They take advantage of the fact that no one knows everyone at a big wedding. And they don’t hide out in corners; they are the life of the party. The crashers dance with flower-girls and grandmothers, they propose meaningful toasts about soul-mates and guide the new couple through the cake-cutting, they entertain children with magic tricks and balloon animals, and they make everyone around them feel good about themselves.

That these steps serve to get bridesmaids and other available women in bed with them at the end of the night is treated as a footnote to their antics, since the two are clearly as high on the nuptial endorphins as their female counterparts.

John and Jeremy meet their match, however, when they encounter the Cleary sisters at the “Kentucky Derby of weddings”, a high-society affair with well-connected and wealthy society doyens watching their impeccably groomed off-spring sipping champagne and chatting about sailing and summer homes as they stroll on impeccably groomed lawns.

Jeremy goes after Gloria Cleary (Isla Fisher), a perky bridesmaid turned “stage 5 clinger” who turns out to have a vibe somewhere on the brink between scary stalker and intriguingly kinky. This leaves Jeremy on the brink between terrified and mesmerized.

John is drawn to Claire Cleary (Rachel McAdams), who has a dazzling smile and an ambivalence similar to his own when it comes to weddings, love, and family. They connect, she reveals she has a fiancé (an arrogant preppy destined for a downfall). John chases her, he is revealed, he pines, he makes a last attempt to demonstrate his love.

Cleary parents (Christopher Walken and Jane Seymour) are caricatures, both humorous but with few surprises, except perhaps Treasury Secretary Cleary’s inexplicable switch from upper-class snob to loving father. Certainly Mrs. Cleary’s substance abuse and Mrs. Robinson-style come-on are neither surprising or amusing.

And the laughs seem harsher and the movie’s tone more sour in scenes featuring Cleary brother, Todd (Keir O’Donnell), who is a rejected artist desperate for his father’s approval and portrayed for laughs as a predatory homosexual. Mean-mouthed Grandma Mary (Ellen Albertini Dow) spouts invective including derogatory terms to the embarrassment of family. The attempts at mining comedy from homophobia and outrageous comments made by the elderly are the film’s weakest moments.

Immature “innovator” Chazz (Will Ferrell -– who else? -— in a spot-on cameo), Jeremy’s guru for the wedding-crasher ethos, serves as the terrifying ghost-of-the-future for John as he introduces him to “funeral crashing”, a morbid twist on using those events’ heightened emotions for his own interests.

It comes as no surprise that everyone turns out just fine although they all have scenes of humor and humiliation along the way. Vaughn is the movie’s comic center and his wild, improvisational, always off-center riffs are bracingly funny. The repartee between John and Jeremy is zingy and quick, and some scenes were completely inaudible due to audience laughter. McAdams is spirited and lovely and Fisher makes borderline stalkerism funny and appealing. And director David Dobkin (who also directed Wilson in Shanghai Knights and Vaughn in the under-appreciated Clay Pidgeons) has a sure sense of pacing and an expert sense of what is funny.

While the cast are clearly enjoying themselves and the banter is funny, this party is not for all audiences and many will find that the movie’s answers -– that the ends can justify the means, that no wingman can go too far, and that lying and manipulation can be fun for the whole family — are a regrettable hang-over.

Parents should know that this movie is very raunchy. While starring cast members and humor similar to Dodgeball, Old School, and Anchorman, the whole premise of this film puts it in another category. The primary goal of the two main characters is to have as much meaningless sex as possible and to achieve this through lies and manipulation. It is hardly redeemed by an ending that half-heartedly comes down on the side of love, telling the truth (sometimes), and (sort of) monogamous relationships. Scenes include a series of women flopping topless onto bed, women initiating American Pie styled attack sex, public sex-acts, and references to cheating, phone-sex, lap dances, and ménage-a-trois, and a non-sexual same-sex kiss. The language in this movie is very strong and explicit and includes harsh terms for gays, Italians and other groups. A character slips a rival a nausea-inducing drug (supposedly comic), a parent drinks heavily and refers to prescription medication, a character drinks to feel better, people drink to celebrate and to forget. A child makes a joke about marijuana. Fist fights are unfair and painful and a character is shot in the rump, which is played for laughs. Some of the humor borders on homophobia and the gay character is very creepy.

Parents might want to talk with teenagers who see this film about how sex is portrayed as a casual amusement, while love is still held out as the ultimate goal. As the sexiest scene in the movie is actually a fairly chaste kiss, families might want to talk about how the relationships portrayed are often deeper for not having sex involved. While they love and support one another, John and Jeremy fight when one becomes more seriously involved in a relationship. Why is this breaking the rules? Why is the other so emotionally hurt? Finally, the depiction of the Cleary family portrays a fractured but supportive group. How do they show love and support and how do they hurt one another?

Families that enjoy this movie might wish to see Dodgeball, American Pie 3: An American Wedding, Old School, or the previous generation of mature-content comedies such as Animal House or Caddyshack.

Thanks to guest critic AME.