Ron Howard’s “The Dilemma” presents the viewer with one. Is it OK to laugh at what was plainly intended as a semi-serious relationship dramedy? Because the best scenes in this Vince Vaughn/Kevin James buddy picture, where one buddy’s wife is cheating on him and the other buddy finds out, give us more to chew on than laugh about.

And that uncertainty — “Wait, is that supposed to be funny?” — makes the movie an unsatisfying if often surprising experience, a less warm and fuzzy “Parenthood” from a director long removed from his warn and fuzzy years.

Vaughn and James are partners in a Chicago auto-engineering business. Ronny (Vaughn) is the seller with a patter, prone to quoting the pre-game speech from the Kurt Russell hockey picture “Miracle” in “big game” moments.

“Great moments are born from great opportunity…”

Nick (James) is the tech guy, the one who makes their promises to Chrysler come true. Their big idea — give electric cars that rumble and shake, what Nick (James) calls “the visceral experience” of muscle cars.

Ronny? He just wants to make electric cars less “gay.”

But as Nick burns the midnight oil, trying to get the right sound and shake out of a re-fitted electric Dodge, Ronny is trying to get up the gumption to propose to sexy chef Beth (Jennifer Connelly). A wit might think “Dude’s never been married, and he’s 40. And he won’t propose to Jennifer Connelly? Maybe he shouldn’t be calling cars ‘gay.’”

As he scouts for the perfect place to propose, Ronny stumbles across an assignation — Nick’s wife, Geneva (Winona Ryder, in top form) is making out with a rich, hunky younger man, played by Channing Tatum.

Thus, Ronny’s dilemma. To tell Nick, how to tell Nick, when to tell Nick that won’t mess up their deadline with Chrysler. Or to confront Geneva. Or ask Beth for advice. What is the “Guy Code” in such situations?

“It’s all about trust,” Ronny frets. And as he frets, he starts to lie. He has flashbacks, as director Howard feels the need to literally show the fib Ronny is shaping in his head. Funny.

But the lies and a cracked, veiled and funny anniversary party toast make everybody wonder if Ronny’s little “problem” is back in his life, an element shoehorned into this “issues” oriented script.

Vaughn slows down his vintage Vince patter for this. He’s still funny, but he’s losing his fastball. So Queen Latifah comes in and broadly chews it up as a Chrysler exec who uses all manner of inappropriate sexual analogies in praising their car concept. And then there’s Tatum, playing Zip, Geneva’s paramour. Ronny spies on them and gets into an epic tussle with this tattooed, pill-popping freak, given a manic hilarity by Tatum in the finest performance of his male mannequin career.

James always tries too hard, but Vaughn picks his moments to turn it up and blow it out. Connelly brings a sensitive touch. But Ryder, giving her unfaithful wife more of an edge than the namby-pamby script calls for,  reminds us, in a single funny-poignant scene, what she’s capable of as an actress. She’s so good she left Howard with a real dilemma — how not to make this movie totally about her and how not to see everything from her point of view. The evidence from “The Dilemma” is that he never does work that.

See for Yourself
“The Dilemma”

Cast: Vince Vaughn, Winona Ryder, Kevin James, Queen Latifah, Jennifer Connelly, Channing Tatum

Director: Ron Howard

Running time:  1 hour 57 minutes

Rating: PG-13 for mature thematic elements involving sexual content.