'The Dilemma' review: Weirdly existential

In the very first scene of "The Dilemma," a seemingly perfect wife in a seemingly perfect marriage asks, "How long does it take to really know someone?"

In trying to answer, the movie grapples hard with the thorny matter of honesty and relationships and trust. All of us struggle to comprehend, communicate and connect with The Other: pretty heady stuff for a mainstream bromance. Despite bursts of hilarity and an A-list cast, this is a dark, difficult, weirdly existential film - like some seriocomic spin on "I and Thou."

"The Dilemma" was directed by Ron Howard and written by Allan Loeb, who shares the blame for "Wall Street: Money Never Sleeps." This time, in a talky, combative script, Loeb introduces us to two Chicago couples: Ronny (Vince Vaughn) and his girlfriend Beth (Jennifer Connelly); and Nick (Kevin James) and his wife, Geneva (Winona Ryder).

Geneva, who lobs that opening question, is secretly boinking Zip (Channing Tatum), a dim boy with plentiful tattoos and a lachrymose streak. Ronny spots the pair snogging between ferns in a botanical garden, and from then on, he's riddled with doubt. Should he tell Nick his wife his cheating on him, or should he stuff it?

As Ronny obsesses over his buddy, he expresses his concern in increasingly inappropriate ways: stalking, breaking and entering, voyeurism, assault with guitar. It doesn't take long to realize that Nick's problem isn't the story here at all. Ronny's is the story - and he's losing it, fast. As he did in "The Break-Up," Vaughn uses his knack for high-grade Woody Allen nattering as a kind of verbal battering ram, mercilessly pounding everyone into submission. He's funny and more than a little scary, but he also gets to show off his sensitive side: he weeps, he prays.

Saline shows up elsewhere, too, most notably in a fake-crying diner demo in which Ryder is terrific. In other scenes, she is brittle and unlikable; James is panicky from start to finish; Connelly, as the only real grown-up in the picture, glides through it all with mature detachment. None of the romantic couplings has much pizzazz: The real chemistry in the movie, and the only real relationship, is between the two male leads.

-- Advisory: Mature thematic elements involving sexual content.

E-mail Amy Biancolli at datebookletters@sfchronicle.com.

This article appeared on page E - 8 of the San Francisco Chronicle